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SPRINGER BRIEFS IN APPLIED SCIENCES AND TECHNOLOGY  MANUFACTURING AND SURFACE ENGINEERING

Umar M. Al-Turki · Tahir Ayar Bekir Sami Yilbas Ahmet Ziyaettin Sahin

Integrated Maintenance Planning in Manufacturing Systems

SpringerBriefs in Applied Sciences and Technology Manufacturing and Surface Engineering

Series editor Joao Paulo Davim, Aveiro, Portugal

For further volumes: http://www.springer.com/series/10623

Umar M. Al-Turki Tahir Ayar Bekir Sami Yilbas Ahmet Ziyaettin Sahin •

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Integrated Maintenance Planning in Manufacturing Systems

123

Umar M. Al-Turki Tahir Ayar Ahmet Ziyaettin Sahin King Fahd University of Petroleum and Minerals Dhahran Saudi Arabia

Bekir Sami Yilbas Mechanical Engineering Department King Fahd University of Petroleum and Minerals Dhahran Saudi Arabia

ISSN 2191-530X ISSN 2191-5318 (electronic) ISBN 978-3-319-06289-1 ISBN 978-3-319-06290-7 (eBook) DOI 10.1007/978-3-319-06290-7 Springer Cham Heidelberg New York Dordrecht London Library of Congress Control Number: 2014936869  The Author(s) 2014 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)

Preface

Traditionally, maintenance is viewed as the necessary challenge that needs to be controlled and shrunk down to an affordable size. This view is wide spread in all sectors, manufacturing and service, public and private, small and large organizations. Only when an asset is acquired or constructed the maintenance role starts with the objective of keeping the asset available for operation as much as possible. The role of maintenance is complete when the decision of disposing or demolishing the asset is made. This view has changed since the last decade and will continue to change in the coming years driving a change in the way maintenance is planned, managed, and executed. The manufacturing sector is the first to realize the major role maintenance can play in increasing the competitive edge of the organization in a globally competitive market. It is recognized that maintenance should play a role in the whole life cycle of the asset from procurement and installation stage to operational stage to its decommissioning stage. In addition, it is realized that maintenance is the major contributor to the safety of the working environment as well as the global environment. Maintenance is becoming involved in strategic decisions related to asset acquisition, product design, customer satisfaction, and manufacturing sustainability. As the scope of maintenance widens to encompass larger responsibilities, its planning process moved from a local functional planning to a more strategic planning linked to corporate business strategies. Plans that are horizontally integrated with other functional units such as production and quality are vertically and strategically integrated with corporate business units. High level of coordination with external contractors, spare part suppliers, and even business partners is becoming essential in a global business environment. This emerging view of maintenance has generated a wave of research and the best practices in the area of integrated maintenance manufacturing planning. Integrated strategic planning methodologies are adopted for generating long-term and short-term plans. New optimization models are developed that integrate resources and objectives across functional units. Supply chain methodologies are adopted for maintenance of logistics across vendor and material inventories. The aim of this book is to introduce the reader to this new global view of maintenance as a strategic role player in modern manufacturing systems. It briefly surveys the components of maintenance systems, including traditional and recent v

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Preface

maintenance concepts and strategies in light of this view. The book gives the reader an insight into the integrated planning process at a global level starting from the business level and ending with the operational level where the plan is implemented and controlled. The result would be a maintenance plan integrated with a production plan that maintains quality and accompanied by a safety system and code of ethics. Usually, these issues are dealt with in an independent manner that might result in semi-optimum results at the implementation stage. Latest studies and reports related to maintenance planning are utilized in shaping up the contents of this book to make it as useful and practical as possible for all types of readers.

Acknowledgments

We would like to acknowledge the role of King Fahd University of Petroleum and Minerals in extending strong support from beginning to end facilitating every means during the preparation of the book. The authors wish to thank their colleagues who contributed to the work presented in the book through previous cooperation with the authors and particular thanks to all their graduate students.

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Contents

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Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Maintenance in Manufacturing Environment: An Overview 2.1 Types of Manufacturing Systems. . . . . . . . . . . . . . . . . . 2.2 Maintenance in Manufacturing . . . . . . . . . . . . . . . . . . . 2.3 Maintenance Management . . . . . . . . . . . . . . . . . . . . . . 2.4 Maintenance Concepts and Strategies. . . . . . . . . . . . . . . 2.4.1 Total Productive Maintenance . . . . . . . . . . . . . . 2.4.2 Reliability Centered Maintenance . . . . . . . . . . . . 2.4.3 Maintenance Strategies . . . . . . . . . . . . . . . . . . . 2.5 E-Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 Intelligent Prognostics . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Integrated Maintenance Planning . . . . . . . 3.1 Global Maintenance System . . . . . . . . 3.2 Strategic Planning in Maintenance. . . . 3.3 The Strategic Planning Process . . . . . . 3.3.1 Key Success Factors . . . . . . . . 3.3.2 Strategic Issues in Maintenance 3.4 Integrated Maintenance Scheduling . . . 3.4.1 Scheduling Techniques . . . . . . 3.5 Performance Measurement System. . . . 3.5.1 Performance Indicators . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . .

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Health, Safety and Sustainability in Maintenance . . . . . . 4.1 Maintenance and Safety . . . . . . . . . . . . . . . . . . . . . . 4.1.1 Maintenance for Safety . . . . . . . . . . . . . . . . . 4.1.2 Methods for Maintenance Safety Improvement . 4.1.3 Safety Measurement . . . . . . . . . . . . . . . . . . . 4.1.4 Safety Legislations . . . . . . . . . . . . . . . . . . . .

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Contents

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Maintenance and Sustainability . 4.2.1 Sustainable Maintenance 4.3 Conclusion . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . .

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Ethics in Maintenance . . . . . . . . 5.1 Maintenance Code of Ethics . 5.1.1 Pre-task Checklist . . . 5.1.2 Post-task Checklist . . 5.2 Conclusion . . . . . . . . . . . . . Reference . . . . . . . . . . . . . . . . . .

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Recent and Future Trends in Maintenance . . . . . . . . . . . . . . . . . .

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Chapter 1

Introduction

Abstract Maintenance involves multidisciplinary arrangements covering planning to execution and it is one of the essential activities of asset management and engineering. Although arrangements pertinent to maintenance in manufacturing can be simplified depending on the line of interest in the engineering field, at the same time, it is getting complicated because of globalization and the involvement of multi-national industries. In this chapter, a general introduction to maintenance planning and engineering, and its contribution to business success are given. Keyword Maintenance planning Maintenance strategies



Manufacturing systems



Globalization



Maintenance is defined as the set of activities, technical, administrative, and managerial, performed during the life cycle of an item, workplace, work equipment, or means of transport, to preserve the value of an asset. The value includes its reliability, availability, productivity and market value. Activities include planning, coordination, financing, and operations. It involves multidisciplinary activities involving people machines equipment spare parts and information. For these reasons, it is difficult to identify the exact number of workers involved in maintenance activities. Data from France and Spain indicate that about 6 % of the working population is involved in maintenance tasks. According to a survey conducted in 2005 in France, maintenance is the most subcontracted function in industry. In Spain, maintenance workers are most often found in the services sector (70 % in 2004), followed by industry (19 %), and construction (10 %). In summary, maintenance is quite complex and globalization made it even more complicated, where multinational companies are interacting to make and maintain a single machine. Companies and governments spend a large portion of their budget in maintenance for reliable, safe, and cost effective operations and services. The consequence of an ill maintained plane or bridge is catastrophic. Ill maintained machine in a manufacturing facility results in significant loss of profit. Inefficient shutdown maintenance for a petrochemical plant costs millions of dollars of production loss and a sudden breakdown of a desalination plant in a city endangers lives of the population. U. M. Al-Turki et al., Integrated Maintenance Planning in Manufacturing Systems, SpringerBriefs in Manufacturing and Surface Engineering, DOI: 10.1007/978-3-319-06290-7_1,  The Author(s) 2014

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1 Introduction

Traditionally, maintenance is studied in isolation of other functions within an organization such as operations, marketing, etc., and in isolation of other supporting and service providing organizations. Various maintenance strategies were developed over time such as preventive maintenance, condition based maintenance, reliability based maintenance and so forth. These strategies scored great success in eliminating unexpected failures and unplanned unavailability’s which usually cause high costs of operations and restoration. The importance of maintenance is evident in various sectors including construction, transportation, airline industry, power, and manufacturing. The later is probably the most developed and matured maintenance application due to its major role in modern economy and business. Modern manufacturing is becoming more automated than ever with more flexible and reliable manufacturing technologies. As such, manufacturing assets, such as automated assembly lines, CNC machines, automatic guided vehicles, robots, and laser based processes, are becoming highly expensive to acquire and maintain. This rapidly changing manufacturing technology puts maintenance in great challenge for maintaining assets in terms of its production availability, reliability, and safety in addition to its financial value. Hence, the success of manufacturing organizations is becoming more critically linked to maintenance. The main purpose of maintenance is to ensure manufacturing asset (machine, equipment or plant) availability and reliability. Availability refers to the readiness of the equipment to operate and produce measured by the probability of being in that status when needed. Reliability refers to its ability to function at any point of time. This is done by carrying out various activities some of which are planned and some are unplanned. As planned maintenance becomes dominant over other unplanned activities, maintenance becomes more efficient and effective. Typically, maintenance involves large number of workforce, spare parts, tools and equipment, and financial resources. Planning for these resources to be ready at the right time in the right quantity with the minimum cost while maintaining safe, health and clean environment is a challenging task. This involves high level of coordination between multiple stakeholders internal and external to the organization. Production, procurement, and quality functional areas are examples of internal stakeholders while contractors, material and spare part suppliers, technology providers are examples of external stakeholders in addition to other organizations within the supply chain. Several books are available on the subject of maintenance planning and engineering. These books, in addition to introducing various maintenance policies and implementation issues, address the traditional maintenance planning process in relation with existing production plans. Most of these books explore the details of the maintenance functions, from planning to implementation. However, there is a need of a bird eye view of maintenance in relation to financial and environmental business objectives and integrated business and operational planning. This need has attracted the attention of researchers and practitioners and effort is put into developing techniques and methods that considers a holistic view of maintenance.

1 Introduction

3

This book is intended to close that gap in maintenance book publishing with recent advances in integrated planning and scheduling, in addition to modern maintenance strategies, health, safety and environment issues in maintenance. The context and focus is on manufacturing sector. Its not intended to go into details of traditional issues and strategies as much as focusing on recent advances and concerns of the manufacturing and production center. However, traditional topics will be introduced as a base for issues in focus. The aim/scope of the book is to introduce the concept of integrated planning for maintenance and production taken into account quality, health and safety, and environment for high global socio-economic impact. The book will provide insight into the planning process at a global level starting from the business level and ending with the operational level where the plan is implemented and controlled. The result would be a maintenance plan integrated with a production plan that maintains quality and accompanied by a safety system and code of ethics. Usually these issues are dealt with in an independent manner that might result in semi optimum results at the implementation stage. This integrative planning is gaining momentum in the research arena as well as in practice. Increasing number of practicing engineers realized the opportunity loss resulting from disjoint planning as well as the increasing conflicts between different departments within the same organization. Researchers noted the problem and addressed it in their research and consulting services. This book gives a framework for planning production and maintenance taken into consideration quality, safety and ethical issues. Putting these accumulated experience and efforts together in a book would set the stage for further improvements and realize the full benefit of that knowledge. This book addresses those who are involved in production and maintenance planning in all types of manufacturing systems. It addresses engineers and managers from industry, researchers, graduate students, and faculty from academic institutions. It is more focused on recent development than traditional practices and it focuses on macro level integrated approach of planning than micro level planning and optimization. In Chap. 2, types of manufacturing systems are briefly discussed in relation to maintenance. Continuous type of production where plants run for long periods of time, as it is in process industries producing chemical and petrochemical products, needs special type of maintenance policies that take into account the high cost of interruption. In this case plant shutdowns have to be carefully planned for the highest possible efficient and effective implementation. Other types of discrete manufacturing differ in their maintenance strategies depending on the type of technology and production structure. More detailed background about manufacturing environment and manufacturing features that influences maintenance methods is introduced in Chap. 2. In the heart of the book is the topic of integrated maintenance planning as an approach that links business level planning with maintenance planning. Such planning approach smoothen operations and aligns planning at all levels for a clear objective. It also brings down the effects of cross functional conflicts to the lowest

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1 Introduction

level. Integrated planning is recognized lately as a major factor in eliminating waste and reducing costs at the maintenance level as well as organizational level. Chap. 3 of this book explores integrated maintenance planning concept and its development process. It also focuses on performance measurement system as a major part for continuous improvement at all level. The performance measurement system is the most critical tool that links and integrates all levels of maintenance with higher levels in organization management as well other functional area. Health and safety issues when viewed as integral part of the maintenance system becomes more critical and more successful than viewing it as an isolated component with its own objectives and targets. A view of health and safety as an integral part of the maintenance system planning is presented and discussed in Chap. 4. Sustainability concept is gaining global attention and it is dealt with seriously at global level by enforcing policies and legislations. This issue is discussed in this chapter from the maintenance perspective. Ethics, as part of all professional bodies, is discussed in Chap. 5. Ethical values and codes of ethics is part of the integrated maintenance system that needs to be disseminated among maintenance professional at the management, engineering and craftsmen levels. The book is concluded with future trends in maintenance management in Chap. 6.

Chapter 2

Maintenance in Manufacturing Environment: An Overview

Abstract Maintenance is one of the major activities in manufacturing as it highly influences production quality and quantity and directly affects production cost and customer satisfaction. As new manufacturing technologies emerge and global communication advances, new maintenance practices are developed to cope with these changes. The role of maintenance in maintaining asset value over time is getting more visible at the business level with the increase in its acquisition and maintenance costs. In this chapter, various manufacturing systems are introduced along with their distinctive features that influence maintenance strategies and practices. Maintenances management concepts, philosophies, policies, and practices in manufacturing are briefly described and discussed in this chapter. Keyword Maintenance concepts

 Strategies  Manufacturing systems

Maintenance in its narrow meaning includes all activities related to maintaining a certain level of availability and reliability of the system and its components and its ability to perform at a standard level of quality. It includes activities related to maintaining spare part inventory, human resources and risk management. In a broader sense, it includes all decisions at all levels of the organization related to acquiring and maintaining high level of availability and reliability of its assets. Maintenance is becoming a critical functional area in most types of organizations and systems such as construction, manufacturing, transportation, etc. It is becoming a major functional area that effects and affected by many other functional areas in all types of organizations such as production, quality, inventory, marketing and human resources. It is also getting to be considered as an essential part of the business supply chain at a global level. Maintenance plays a major role in the success of organizations in various sectors. However, maintenance in the manufacturing sector attracted special attention puts maintenance in manufacturing in a leading position of development in maintenance. This attention is mainly due to the special features of the manufacturing sector. In this chapter, types of manufacturing systems are classified and U. M. Al-Turki et al., Integrated Maintenance Planning in Manufacturing Systems, SpringerBriefs in Manufacturing and Surface Engineering, DOI: 10.1007/978-3-319-06290-7_2,  The Author(s) 2014

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Maintenance in Manufacturing Environment: An Overview

manufacturing systems

Continuous

Intermittent

production

production

Mass and flow production

Process production

Batch production

Flexible manufacturing

Jobbing production

Project production

Fig. 2.1 Types of manufacturing systems

its different types are introduced. Features that distinct manufacturing from other sectors are discussed along with their influence on maintenance strategies. Finally, maintenance concepts and strategies are briefly introduced.

2.1 Types of Manufacturing Systems The oldest type of manufacturing system is the custom manufacturing where a person or a machine makes a certain product tailored to a specific need. A shoemaker is an example of this system. Modern manufacturing have intermittent, continuous or flexible production systems as shown in Fig. 2.1. Intermittent production is where more than one of the same product is being made in a short amount of time. There are structures of intermittent systems including batch production, jobbing production, project production. In Batch production a group of similar products (batch) are produced stage by stage over a series of workstations. Batch production has a relative low initial set up cost for single production line used to produce several products. This feature makes attractive for small businesses who cannot afford to run continuous production lines. In addition, batch production reduces the risk of unpredictable and seasonal demands. Inefficiencies associated with batch production is the main drawback of batch production as equipment must be stopped between batches for a while (idle time) to re-configured and tested. Jobbing production is where firms produce items that meet the definite requirements of the client as a one-off. These items are designed differently, and are tailored to the needs of each individual client. They include tailoring, plumbing, film production and new transport systems installation. In Project production a complex sets of interrelated activities (project) are performed within a given period of time and estimated budget to make a product characterized by its immobility during production. Examples of such products are;

2.1 Types of Manufacturing Systems

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ships, locomotive, aircrafts buildings and bridges. The product is located in a fixed position where production resources are moved to it. Network planning techniques, such as PERT and CPM, are usually utilized for scheduling and controlling the implementation of the project. The most flexible and responsive to changes manufacturing system is the flexible manufacturing system (FMS). It absorbs sudden large scale changes in production volume, capacity and capability. FMS produces a product just like intermittent manufacturing and is continuous like continuous manufacturing. Flexibility is coming from either the ability to produce new products (machine flexibility) or from the ability to use multiple machines to perform the same operation (routing flexibility). Usually, FMS consist of highly automated CNC machines connected by sophisticated material handling system and a central computer that controls material movements and machine flow. The main advantage of FMS is its high flexibility in managing manufacturing resources. The resulting gains are numerous including: • • • • • •

Reduced manufacturing cost, Greater labor productivity, Greater machine efficiency, Improved quality, Increased system reliability, Shorter lead times.

However, FMS implementation requires a large initial capital and substantial preplanning. It also requires high skilled labor. Continuous manufacturing is the type of manufacturing system that uses an assembly line or a continuous process to manufacture products. It is used for products that are made in a similar manner. In this type of manufacturing system the product moves and processed along the production line. Continuous processing is a method used to manufacture or process materials that are either dry bulk or fluid continuously through a certain chemical reaction or mechanical or heat treatment. Continuous usually means several months or sometimes weeks without interruption. Some common continuous processes are; Oil refining, Chemical and petrochemicals plants, sugar mills, blast furnace, power stations, and saline water desalination and cement plants. Continuous processes use process control to automate and control operational variables such as flow rates, tank levels, pressures, temperatures and machine speeds. Different maintenance approaches are usually adopted for different types of manufacturing systems. Shut down maintenance is commonly used for major overhauls in continuous manufacturing systems. Shutting down and starting up continuous processes typically results in waste or degraded products and it usually takes several hours for production to resume in full capacity. Strict procedure should be followed for shutting down and starting up continuous manufacturing processes to protect personnel and equipment. In contrast, discrete or semi-continuous manufacturing processes can be easily shut down and restarted and can be operated for

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Maintenance in Manufacturing Environment: An Overview

one or two shifts if necessary. Flexible manufacturing systems give higher flexibility for planned and unplanned maintenance activities compared to other types of manufacturing systems.

2.2 Maintenance in Manufacturing Maintenance in the manufacturing environment is one of the most complicated types of maintenance in comparison to construction, transportation and service business. Manufacturing is becoming highly competitive with extremely high pressure in reducing cost and increasing value of assets and improving the quality of outcomes (products). Manufacturing systems has grown over the years to be parts of global networks and supply chains. All of these changes in the manufacturing business have put maintenance in a great pressure on developing more effective and efficient operations. Other special feature of manufacturing environment that makes it distinct from other environment is its complicated interrelation with large number of stakeholders, internal and external. The management structure in manufacturing environment is usually highly structured with many several decision layers and many parallel functional areas. Marketing, purchasing, production, engineering, and maintenance are common functional areas that usually share the benefit of the manufacturing facilities in different objectives that in many cases are conflicting with each other and hence proper synchronization is essential for the success of the global manufacturing business. External beneficiaries (stakeholders) include contractors, technology and spare part providers, customers, and upstream and downstream customers in the supply chain. Coordination and may be integration is essential for globally competitive business environment. Manufacturing facilities are in the heart of all of this complicated interrelation which makes maintenance a critical role player in this environment. Maintenance in manufacturing deals with highly technical equipment that needs special types of expertise with limited choices of technology providers. As such maintenance in manufacturing requires highly sophisticated level of planning and operations more than any other business environment. Developing internal expertise in these technologies is becoming more and more expensive and choice for outsourcing is limited. Various maintenance strategies are adopted regarding inhouse versus outsourcing for higher asset value, and more productivity operations. Manufacturing facilities usually have long term physical interaction with limited number of people that are usually well trained to handle major production equipment. However, those people are exposed to health and safety hazards resulting from ill maintained facilities and equipment. As such maintenance plays a major role in keeping healthy environment locally within the facility, and the global environment. Waste resulting from manufacturing processes can be reduced and controlled through proper maintenance and asset management practices. Health and safety of people within the manufacturing facility can be well improved and

2.2 Maintenance in Manufacturing

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Labor Material

Enterprise System Production System

Output

Spares Availability Tools Maintenance

Maintainability

Information Money

Safety

External Services

Profits

Fig. 2.2 Input output model of the enterprise

sustained through well planned and managed maintenance. The issue of health and environment in manufacturing is highly critical compared to other businesses as it is considered to be one of the main sources of environmental hazards in the current industrial arena. This needs clear and global understanding of maintenance as a part of a large system that works together for the benefit of the whole organization. One such view is introduced by Visser [1] as shown in Fig. 2.2. Maintenance is in the heart of the production system that is part of a global enterprise. The success of the enterprise is highly dependent on the output of the production system in terms of quantity, quality, and safety. Such output cannot be obtained without a highly effective and efficient maintenance system that maintains high rate of manufacturing equipment availability with long term maintainability that keeps high level of asset value. Such maintenance system is composed of plans and operations that guarantees material, spares, tools, human and financial resources availability in the right time with the right quality and quantity. External resources and outsourcing some activities are some strategies that may be utilized as needed in the right way.

2.3 Maintenance Management The main decisive factor for maximizing manufacturing asset value in terms productivity, reliability, cost, etc. is maintenance management, the body of the organization that is in charge of planning, implementing, controlling, and improving maintenance activities. Maintenance management is often considered as a centralized functional unit within the overall organizational structure in

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Maintenance in Manufacturing Environment: An Overview

Fig. 2.3 Hybrid maintenance organizational structure

Operations

Central maintenance unit

Production Unit

Maintenance Sub-Unit1

Production Sub-Unit 1

Maintenance Sub-Unit 2

Production Sub-Unit 2

Maintenance Sub-Unit 3

Production Sub-Unit 3

parallel with other functional units such as, production, Decentralized maintenance units is another common structure adopted by large organizations with multiple production units. The decision of adopting centralized or decentralized management structure is usually mad at the high management level taking into consideration, the size of the organization, the complexity of its operations, and the organization culture. Each structure has its advantages and disadvantages. Advantage of centralized over decentralized are: Centralized structure is more efficient in utilization of specialized human resources and equipment. Decentralized structure provides higher accessibility and responsiveness and more quality results. Small and medium size organizations prefer centralized structure because of cost and limited amount of work. Large size organizations vary between the two choices. A third common option is a hybrid structure that keeps maintenance units (group) at each production unit linked to a central maintenance unit as shown in the Fig. 2.3. This structure preserves close access and high level of specialization and interaction with production while utilizes collective expertise and support in the central unit with less cost. Maintenance management involves planning, organizing, and controlling responsibilities. Maintenance planning is done at three levels, strategic, tactic and operations. The maintenance strategic planning level is to establish the alignment with higher business level plans. The details of this level of planning are covered in Chap. 3. Tactical and operational plans include the following elements: 1. 2. 3. 4.

Maintenance Maintenance Maintenance Maintenance

philosophy load forecasting capacity scheduling.

Maintenance philosophy is the step of designing on the general maintenance concept selected from known best practices as the maintenance philosophy for

2.3 Maintenance Management

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the organization. Total productive maintenance and reliability based maintenance concepts are two widely spread concepts that are discussed in Sect. 2.3. The selected concept is supported with right combinations of maintenance strategies such as preventive maintenance, condition based maintenance, and shutdown maintenance. Brief discussion on these strategies is introduced in Sect. 2.4. Maintenance forecasting is a major part of planning concerned with estimating the current and future amount of maintenance work and type needed. Maintenance load forecasting is a complex task that involves a lot of uncertainties and influenced by many factors such as the age of the equipment, the rate of use, usage climate, and skills of workers. Capacity planning is the translation of the maintenance load into resource needed to meet the forecasted load. Resources include, number and skills of craftsmen, maintenance tools, labor, material, spare parts, etc. Maintenance scheduling is the process of assigning resources for tasks to be accomplished at a certain time in a certain frequency. Scheduling of tasks should take into account production schedules, optimization of resources and reducing costs. Scheduling is discussed in Chap. 3 in detail. The organizing responsibility of maintenance management includes: 1. Job design 2. Time standards 3. Project management. Job design involves defining for each major maintenance job, the work content, the method of maintenance the required skills and the needed tools. Time standards are determined for major components of major maintenance jobs following the scientific approach. This helps in controlling maintenance tasks and efficient utilization of resources. It is also useful for planning and scheduling maintenance activities and forecasting workload. Project management is used for optimizing and controlling major complex time consuming maintenance operations, such as shutdown maintenance projects for large plants. Critical Path Method (CPM) and Program Evaluation and Review (PERT) are common project management tools. Controlling activities of maintenance management include the following: 1. 2. 3. 4.

Work Control Inventory Control Cost Control Quality Control.

Work control is done using work order system in an integrated data base system for controlling reporting and analyzing. Intelligent maintenance systems are developed and integrated with ERP systems are commonly used and proven to be efficient and effective. Inventory control is an important element of maintenance management that ensures the availability of spare parts and tools in the right quantity at the right

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Maintenance in Manufacturing Environment: An Overview

time. Ordering and re-ordering quantities taking into consideration costs and lead times are built into automated information systems to assist management in this task by raising red flags at reorder points. Cost control involves tracing all cost components of maintenance activities that include direct maintenance costs, lost production, equipment degradation, backups, and over maintenance costs. Quality control of maintenance work involves assuring that the maintenance work is following standards and producing the expected results. Control is done by the supervision and testing final outcomes following a predetermined control procedure.

2.4 Maintenance Concepts and Strategies Several maintenance concepts were developed in different parts of the world that are usually based on cultural and philosophical backgrounds. These trends encompass other strategies and technologies of maintenance. Some of these concepts are briefly introduced below:

2.4.1 Total Productive Maintenance Total Productive Maintenance (TPM) is developed from the preventive maintenance methodology introduced from the USA and further developed and implemented in many Japanese companies since 1971. It is then spread throughout the world. TPM is defined as a system of maintaining and improving the integrity of production and quality systems through the machines, equipment, processes and employees that add business value to the organization [2]. Total Productive Maintenance (TPM) is a proactive and cost-effective approach to maximize equipment effectiveness using the principles of teamwork, empowerment, ‘zero breakdowns’ and ‘zero defects’. TPM is designed to maximize equipment effectiveness (improving overall efficiency) by establishing a comprehensive productive-maintenance system covering the entire life of the equipment, spanning all equipment related fields (planning, use, maintenance, etc.) and, with the participation of all employees from top management down to shop-floor workers, to promote productive maintenance through motivation management or voluntary small-group activities. TPM provides a comprehensive company-wide approach to maintenance management, which can be divided into long-term and short-term elements. In the long-term, efforts focus on new equipment design and elimination of sources of lost equipment time and typically require the involvement of many areas of the organization. In this chapter, we focus on the short-term maintenance efforts that are normally found at the plant

2.4 Maintenance Concepts and Strategies

13

level of the organization. In the short-term, TPM activities include an autonomous maintenance program for the production department and a planned maintenance program for the maintenance department. TPM improves many aspects such as operational performance, safety, cleanliness, employee morale and customer satisfaction to achieve excellence in business performance [3]. Some of the key objectives of TPM are: • Focus and improve people management to minimize the targeted losses. • Develop the policy, strategy and early management activities to ensure easy maintenance of the equipment. • Develop the autonomous maintenance system to empower the production operators to take care of the conditions and effectiveness of the equipment. • Develop a planned maintenance of the machine and equipment. • Provide training and education to the operators and maintenance personnel to upgrade their equipment-related knowledge and skills. • Establish safety practices and also prevent adverse environmental effects. • Reduce the wastage of organizational resources. Research show strong positive impact of TPM on multiple dimensions of maintenance performance [4]. In addition to controlling costs, TPM can improve dimensions of cost, quality, and delivery and it can be a strong contributor to the strength of the organization. There are seven major elements of TPM as follows [5]: 1. 2. 3. 4. 5. 6. 7.

housekeeping on the production line, cross-training of operators to perform maintenance tasks, teams of production and maintenance personnel, operator involvement in the maintenance delivery system, disciplined planning of maintenance tasks, information tracking of equipment and process condition and plans, Schedule compliance to the maintenance plan.

The main barriers to implementing TPM are lack of top management commitment, lack of middle management support and employee resistance to change. Changing the environment to suit TPM is a challenging task in the public sector undertakings, where apart from normal business constraints, managers deal with stiffer government control, large and unwieldy operations, wary unions and bleeding bottom lines.

2.4.2 Reliability Centered Maintenance Reliability Centered Maintenance (RCM) was initiated by the commercial aviation industry and then adopted by the U.S. military in the 1970s and then by the U.S. commercial nuclear power industry (in the 1980s) followed by other commercial

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industries and fields in the early 1990s. The following brief introduction is adopted from http://www.ebme.co.uk/articles/management/327-reliability-centredmaintenance-rcm in addition to other recent sources from the literature. RCM is defined by the technical standard SAE JA1011, as ‘‘an engineering framework that enables the definition of a complete maintenance regime. It regards maintenance as the means to maintain the functions a user may require of machinery in a defined operating context’’. It is an industrial improvement approach focused on identifying and establishing the operational, maintenance, and capital improvement policies that will manage the risks of equipment failure most effectively. Within the manufacturing context, RCM is a systematic approach for understanding the function of the manufacturing system and the failure modes of its components, and choosing the optimum course of action that would prevent the failure modes from occurring or to detect them before occurring. The primary principles upon which RCM is based are the following: • Function oriented. It seeks to preserve system or equipment function. • Device group focused. It is concerned with maintaining the overall functionality of a group of devices rather than an individual device. • Reliability centred. It uses failure statistics in an actuarial manner to look at the relationship between operating age and the failures. RCM is not overly concerned with simple failure rate; it seeks to know the probability of failure at specific ages. • Acknowledges design limitations. Its objective is to maintain the inherent reliability of the equipment design, recognizing that changes in reliability are the province of design rather than maintenance. Maintenance can only achieve and maintain the level provided for by design. • Driven by safety and economics. Safety must be ensured at any cost; thereafter, cost-effectiveness becomes the criterion. • Defines failure as any unsatisfactory condition. Therefore, failure may be either a loss of function (operation ceases) or a loss of acceptable quality (operation continues). • Uses a logic tree to screen maintenance tasks. This provides a consistent approach to the maintenance of all kinds of equipment. • Tasks must be applicable. The tasks must address the failure mode and consider the failure mode characteristics. • Tasks must be effective. The tasks must reduce the probability of failure and be cost effective. • Acknowledges two types of Maintenance tasks and Run-to-failure. The tasks are Interval (Time- or Cycle-)-Based and Condition-Based. In RCM, Run-to-Failure is a conscious decision and is acceptable for some equipment. • A living system. It gathers data from the results achieved and feeds this data back to improve future maintenance. This feedback is an important part of the Proactive Maintenance element of the RCM program. RCM develops maintenance standards for ensuring that a system or device meets its designed reliability or availability, even in the procurement and installation phases.

2.4 Maintenance Concepts and Strategies

15

RCM analysis determines the type of maintenance appropriate for a given equipment item. It results in a decision of whether a particular piece of equipment should be reactively maintained (‘‘Accept Risk’’ and ‘‘Install Redundant Units’’), predicatively maintained (‘‘Define PM Task and Schedule’’) or predicatively maintained (‘‘Define Predictive Testing and Inspection Task and Schedule’’). Successful implementation of RCM results the following benefits: 1. Increased reliability leading to fewer equipment failures and, therefore, greater availability for patients and lower maintenance costs. 2. Reduction in total of total maintenance cost as failures are prevented and preventive maintenance tasks are replaced by condition monitoring. 3. Increasing Efficiency and Productivity as a result of the RCM approach to maintenance that ensures that the proper type of maintenance is performed on equipment as needed. 4. Reducing lifecycle costs including acquisition phase and operation phase since decisions made early in the acquisition cycle profoundly affect the life-cycle cost. Savings of 30–50 % in the annual operations and maintenance costs are often obtained overtime through the implementation of a balanced RCM program. 5. Improving maintenance sustainability as RCM planning involves decisions made at all phases of equipment life cycle.

2.4.3 Maintenance Strategies Maintenance can be performed in two major types: corrective or preventive as shown in Fig. 2.4. Corrective maintenance, similar to repair work, is undertaken after a breakdown when obvious failure has been located. Preventive maintenance (PM) is intended to reduce the probability of failure or degradation of functioning of an item and is carried out at predetermined intervals, predetermined PM, or according to a prescribed condition, Condition Based Maintenance (CBM). Predetermined maintenance is scheduled based on the number of hours in use, the number of times an item has been used, according to prescribed dates, etc. The question remains which equipment should be preemptively maintained and at what times? Condition based maintenance, on the contrary, does not use predetermined intervals and schedules. It monitors the condition of components and systems (diagnostic) in order to determine a dynamic preventive schedule. It can also use forecasted condition of the machine (prognostic) for that purpose. A comparison of different maintenance approaches is shown in Table 2.1. In practice, combination of these approaches is used for different components within the same manufacturing environment.

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Maintenance

Corrective Maintenance

Differed

Immediate

Preventive Maintenance

Condition based

Predetrmined

Scheduled, continuous or on request

Scheduled

Fig. 2.4 Types of maintenance (extracted from Niu, G., et al.)

A brief description of each maintenance strategy is introduced next. 1. Corrective maintenance (also called reactive, breakdown, or operate to failure maintenance) may be defined as the remedial action carried out due to failure, or deficiencies discovered during preventive maintenance, to repair an equipment/item to its operational state. The action can be repairing, salvaging, rebuilding or overhauling. Usually, corrective maintenance is an unscheduled maintenance action, basically composed of unpredictable maintenance needs that cannot be preplanned on the basis of occurrence at a particular time. The action requires urgent attention that must be added, integrated with, or substituted for previously scheduled work items. However, corrective maintenance should be utilized only in non-critical areas where capital costs are small, consequences of failure are slight or does not affect the comprehensive system function, no safety risks are immediate, and quick failure identification and rapid failure repair are possible. In such cases, the maintenance can be deferred until a suitable time. 2. Scheduled Preventive Maintenance (PM) is a scheduled or fixed time maintenance service to detect and prevent potential failures and extend the life of equipment. It includes activities such as cleaning, lubricating, adjustment, and replacement of minor parts. It is used for reducing unexpected failure of critical

2.4 Maintenance Concepts and Strategies

17

Table 2.1 Maintenance strategies (extracted from Niu et al.) Corrective

Preventive

Run-to-fail

Predetermined

Maintenance approaches Fix when it Scheduled maintenance breaks No scheduled maintenance

Predictive

Condition based maintenance diagnostics Maintenance based on a fixed Maintenance time schedule based on current condition Intolerable failure effect and Maintenance possibility of preventing scheduled the failure effect based on evidence of needs Based on the useful life of the Continuous component forecasted collection of during design and updated condition through experience monitoring data Failure mechanism is time Gradual based, age or usage degradation from the onset of failure

Condition based maintenance prognostics Maintenance based on forecasting of remaining equipment life Maintenance need is projected as probable within mission time

Forecasting of remaining equipment life based on actual stress loading Gradual degradation from the onset of failure

equipment and to promote better safety, health and working environment conditions for the workforce. It helps in increasing the life span of assets and eliminates unnecessary replacements. However, PM should be planned and performed in a highly delicate manner to avoid damage of the equipment or nearby equipment during inspection, repair, adjustment, or installing or reinstalling of parts. Timing of PM should also be optimized to reduce risks of failure during or after PM and to minimize total costs of PM while maximizing total benefits. Computer and mathematical models are developed for that purpose. In general, the frequency of PM is determined by the type of equipment, its age, its condition, and the consequences of failure. Optimization models exist for various preventive maintenance policies including replacement and inspection. Consider an example of a replacement policy where a component is replaced after operating for a time t. During this time, minor repairs are performed in case of unexpected component failures. The replacement preventive maintenance brings back the system to as good as new condition, while minimum repair does not change the failure rate of the system. The objective in this case is to find the optimum replacement time t* (period) that minimizes the total cost of replacement

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and minimum repairs. Considering t as the cycle time of replacement, we may consider minimizing the expect cost per unit time UEC(t) as follows: UECðtÞ ¼

Total expected cost expected cycle time

Assuming random component failures of failure rate r(t), the expected number of failures E[N(t)] during time period (0, t) is given by Barlow and Hunter [6] as follows:

E½N ðtÞ ¼ H ðtÞ ¼

Zt

r ðtÞdt;

0

This makes the expected unit time cost modeled as follows: UECðtÞ ¼

Cp þ Cf HðtÞ ; t

where, Cp is the total cost of replacement and Cf, the cost of each minimum repair. Now solving the equation with respect to t gives the optimum time for replacement t* that gives the minimum cost per unit time. Other models for more complicated situations can be found in the literature of PM optimization. 3. Condition based maintenance (CBM) was introduced to try to maintain the correct equipment at the right time. CBM is based on using real-time data to prioritize and optimize maintenance resources. Observing the state of the system is known as condition monitoring. Such a system will determine the equipment’s health, and act only when maintenance is actually necessary. Developments in recent years have allowed extensive instrumentation of equipment, and together with better tools for analyzing condition data, the maintenance personnel of today are more than ever able to decide the right time to perform maintenance on some piece of equipment. Ideally condition-based maintenance will allow the maintenance personnel to do only the right things, minimizing spare parts cost, system downtime and time spent on maintenance. http://en.wikipedia.org/wiki/Condition-based_maintenance. The most common condition monitoring techniques are vibration analysis, oil analysis, thermography, ultrasonics, electrical effects monitoring and penetrants. Vibration analysis techniques are used to monitor the performance of mechanical equipment that rotates, reciprocates, or other dynamic actions. Examples include gearboxes, roller bearings, motor, fans, generators and reciprocating engine. Oil analysis looks at its chemical composition and its content of foreign material. Iron based wear particles in lubrication oils determines the specific component that is wearing and the type and extent of wear. Changes in lubricant properties, including viscosity, flash point, pH, water content, etc. reflect the condition of the equipment.

2.4 Maintenance Concepts and Strategies

19

Thermography measures surface temperature variations using infrared camera to determine poor electrical connections and hot spots furnace and kiln refractory wear and critical boilers and turbine component overheating. Ultrasonics are used to detect cracks, gaps, build ups, erosion, and corrosion in welds, coatings, piping, tubes, structures, shafts, etc. Electrical effect monitoring is used for corrosion detection. Electrostic and liquid-dye penetrants are used to detect cracks and discontinuities on surfaces. In reality, reliable and effective CBM faces some challenges. First, initiating CBM is costly. Often the cost of instrumentation can be quite large, especially if the goal is to monitor equipment that is already installed. Second, it is not always easy to implement CBM due to variables such as complexity of the environment, the inner structure of equipment, obscure failure mechanisms, etc. The advantages of CBM over predetermined preventive maintenance: • Improved system reliability • Decreased maintenance costs • Decreased number of maintenance operations causes a reduction of human error influences. Its disadvantages are: • High installation costs, for minor equipment items often more than the value of the equipment • Unpredictable maintenance periods cause costs to be divided unequally • Increased number of parts (the CBM installation itself) that need maintenance and checking. Today, due to its costs, CBM is not used for less important parts of machinery despite obvious advantages. However it can be found everywhere where increased reliability and safety is required, and in future will be applied even more widely. 4. Shutdown maintenance is a planned stoppage of production for conducting a comprehensive maintenance of equipment or plant with the purpose of restoring the processes to its original state. Shutdown is a common practice in continuous type of production systems and it is given different names in different industries such as, shutdown, shut-in, down-turn, turnaround, or outage. During the shutdown period a large complement of work is scheduled into a relatively short period of time. The period might extend to several weeks causing a large amount of planned production loss. Scheduled shutdowns, however, can provide unique opportunities to a maintenance department not normally available during standard operation or even during short shutdown periods. Lost capacity can be restored to an overtaxed facility during an extended shutdown. Major equipment overhauls can be performed to help prevent future unscheduled shutdowns. Long term preparation for the shutdown maintenance involves external contractors, technology providers, and customers.

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Typically oil refineries go through shut down maintenance every 4 years for 42 days with around 300,000 man-hours with around 80 % success rate [7]. Power plant shutdown maintenance projects are larger in duration and man power requirement, while shutdowns in petrochemical industries are more frequent but smaller in terms of duration and man-hour requirement. Shutdown maintenance is usually divided into four phases [8]: a. Initiation: In this phase detailed planning of all aspects of the project is done. This includes, work scope, pre shut down work, procurement of material, quality and safety programs, project organization, cite logistics, etc. b. Preparation: This phase includes the task of defining the work scope in the form of a list of tasks and activities that need to be done during shutdown maintenance. The success of this type of maintenance depends on the clarity of the work scope. In many cases the work scope is usually loosely defined drawn from past experience, inspection reports, and historical estimates. This scope fluctuation causes work force staffing changes during the TAM execution. Several methodologies are reported in the literature for developing clear and concise work scope. Another task in this phase is preparation of the job packages, selection of contractors, defining safety procedure, etc. in addition to the budget. c. Execution is the phase concerned with conducting the work and monitoring its progress in accordance with time, cost and quality. d. Termination is the phase of closing the project, assessing performance and documenting lessons learned. 5. Other maintenance types or activities are done within the above major maintenance strategies include the following: • Opportunity maintenance is an activity conducted when an opportunity arises while performing another major maintenance job. An example of an opportunity is a shutdown maintenance period utilized to carry out known maintenance tasks. • Overhaul is a comprehensive examination and restoration of a piece of equipment to an acceptable condition • Fault finding is the task of assessing the level of failure onset. • Design modification is carried out in coordination with the engineering department or technology provider to improve the operational performance of equipment through design changes. Maintenance exposes the equipment to design faults and improvement opportunities that when carried out improves the overall performance of the system. • Replacement of equipment instead of fixing it upon failure or replacing the equipment following a predetermined plan regardless of its condition at the time.

2.5 E-Maintenance

21

2.5 E-Maintenance E-maintenance is wide spread in the industry since the early 2000, referring to the integration of information and communication technologies with the maintenance strategy following the success of e-business and the e-manufacturing in business and production. Muller et al. [9] define e-maintenance as ‘‘Maintenance support which includes the resources, services and management necessary to enable proactive decision process execution. This support includes e-technologies (i.e. ICT, Webbased, tether-free, wireless, infotronics, technologies), e-maintenance activities (operations or processes) such e-monitoring, e-diagnosis, e-prognosis, etc.’’ The emergence of e-maintenance contributed to increase maintenance efficiency, responsiveness, and proactivness and to optimize maintenance related work flow. It also integrated maintenance with the other functions of the eenterprise. E-maintenance increases accessibility of multi origin data of different types and facilitates remote analysis, prognostics and decision making. Muller et al. [9] identified three categories of capabilities or advantages of emaintenance: 1. Maintenance type and strategies: • E-maintenance provides users, operator, manager, or expert, with remote accessibility to factory’s equipment condition allowing them to take remote actions such as monitoring, diagnosing, de-bugging, fixing, controlling, etc. This capability allows remote decision making and expert consultation without physical attachment to the plant. • E-maintenance provides the opportunity of connecting geographically dispersed subsystems and stakeholders which allows cooperative/collaborative maintenance. This capability contributes to accelerating maintenance processes and simplifies it design (lean process). • E-maintenance allows immediate intervention by operator in response to programmable alerts and seeks on-line expertise for optimum solution to the situation. 2. Maintenance support and tools. • E-maintenance utilizes new development in sensor technology, ICT, signal processing and other similar technologies, in better understanding of causes of failure and system disturbances for improved engineering designs and production techniques. • E-maintenance provides a transparent and automated information exchange platform with different stakeholders. • E-maintenance enables high quality of after-sales service in terms of response time and quality consultation and interventions. 3. Maintenance activities • E-maintenance provides experts with the opportunity of on-line fault diagnosis and share their share their expertise with each other.

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• With e-maintenance provides remote operators rapid interaction with experts and source designers for repairing and trouble shooting. This results a reducing down times. • The multisource knowledge and data environment allows efficient knowledge capitalization and management.

2.6 Intelligent Prognostics Prognosticsis an engineering discipline focused on predicting the health of a system or a component and hence it’s remaining useful life. The predicted health is used for deciding on action to be taken for retaining its original state or contingency mitigation. The science of prognostics is based on the analysis of failure modes, detection of early signs of wear and aging, and fault conditions. These signs are then correlated with a damage propagation model. Prognostics issued in different applications such as maintenance management and transportation. In manufacturing maintenance is used in combination of condition-based maintenance. Intelligent Prognostics is a natural evolution of predictive maintenance utilizing remote networking technologies combined with big data modeling with sophisticated imbedded systems. Lee et al. [10] define intelligent prognostics as ‘‘a systematic approach that can continuously track health degradation and extrapolating temporal behavior of health indicators to predict risks of unacceptable behavior over time as well as pin pointing exactly which components of a machine are likely to fail’’. Technical approaches to building models in prognostics can be categorized broadly into data-driven approaches, model-based approaches, and hybrid approaches. Model base prognostics may include data collected from model-based simulations under normal and degraded conditions. Models are built based on different random load conditions or modes. In the absence of valid, reliable and accurate system models, the trajectory of a developing fault is monitored and the time to reach a predetermined state of intervention is predicted. This is the datadriven prognostic approach. The hybrid approach utilizes both data driven and model based approaches to generate more accurate and reliable results. For more details, see [10]. Maintenance will continue to utilize more tools of Prognostics and integrating it with other intelligent and communication technology. The trend of developing more generic predictive and intelligent maintenance systems for different industrial applications will continue. Intelligent prognostics is the base of the e-maintenance concept that links maintenance with the rest of the production system.

References

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References 1. Visser JK (1998) Modeling maintenance performance: a practical approach. In: Proceedings of the IMA conference, Edinburgh, pp 1–13 2. Prabhuswamy MS, Nagesh P, Ravikumar KP (2013) Statistical analysis and reliability estimation of total productive maintenance. IUP J Oper Manage 12(1):7–20 3. Miyake DI, Enkawa T (1999) Matching the promotion of total quality control and total productive maintenance: an emerging pattern for the nurturing of well-balanced manufacturers. Total Qual Manage 10(2):243–269 4. McKone KE, Schroeder RG, Cua KO (2001) The impact of total productive maintenance practices on manufacturing performance. J Oper Manage 19(1):39–58 5. McKone KE, Schroeder RG, Cua KO (1999) Total productive maintenance: a contextual view. J Oper Manage 17(2):123–144 6. Barlow RE, Hunter LC (1960) Optimum preventive maintenance policies. Oper Res 8:90–100 7. Obiajunwa C, Syngenta (2012) A best practice approach to manage work scope in shutdowns, turnarounds and outages. AMMJ Asset Manage Maintenance J 1:1–7 8. Duffuaa S, Ben-Daya M (2009) Turnaround maintenance. In: Ben-Daya M, Duffuaa SO, Raouf A, Knezevic J, Ait-Kadi D (eds) Handbook of maintenance management and engineering, pp 223–235. Springer, London 9. Muller A, Marquez AC, Iung B (2008) On the concept of e-maintenance: review and current research. Reliab Eng Syst Saf 93:11165–11187 10. Lee J, Ni J, Djurdjanovic D, Qiu H, Liao H (2006) Intelligent prognostics tools and e-maintenance. Comput Ind 57:476–489

Chapter 3

Integrated Maintenance Planning

Abstract Maintenance planning and scheduling require utilization of resources at a maximum level. Integrated maintenance planning is an approach in planning that takes into consideration global production systems at the business level. It considers the expectation of all internal and external stakeholders of the maintenance function to secure the maximum benefits from the whole system. In this chapter, the process of high level (strategic) planning that links maintenance strategies to business and production strategies is described. The traditional low level (operational) planning and scheduling linked with the strategic level plan is also described. Keywords Strategic planning mance management



Operations planning and scheduling

 Perfor-

Integrated maintenance planning and scheduling secures a maximum utilization of resources at the global system level. In this chapter a global view of maintenance that considers its internal and external stakeholders will be introduced followed by a detailed process for high level planning that links these stakeholders together for the maximum benefit of the whole system. Lower level planning and scheduling at the plant level is then introduced in its traditional way followed by a nontraditional scheduling that integrates scheduling within the organization is introduced. Lastly a performance management system is described for different levels or the organization.

3.1 Global Maintenance System The global manufacturing environment involves multiple internal and external stakeholders that need to be considered for an integrated planning process. Production and quality are major internal functional stakeholders for maintenance. Other internal stakeholders at the business level include top management, purchasing, finance and marketing departments. External stakeholders may include, U. M. Al-Turki et al., Integrated Maintenance Planning in Manufacturing Systems, SpringerBriefs in Manufacturing and Surface Engineering, DOI: 10.1007/978-3-319-06290-7_3,  The Author(s) 2014

25

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3 Integrated Maintenance Planning

Technology Providers

Contractors (HR)

Spare parts suppliers

Vendors part & equipment Plant 1

Plant 2

Plant 3

Customer

Raw material Supplier

Fig. 3.1 Global view of maintenance

depending on the type of maintenance, contractors, spare parts and technology providers, and government legislators. Ignoring one or more of the key stakeholders may result in unnecessary costs and sometimes more serious consequences at the business level. A system view of the manufacturing system was introduced by Al-Turki et al. [1]. The material in this section is extracted from that source. A global system view of the maintenance business interrelation with other entities is shown in Fig. 3.1. The figure also shows the supply chain relationship starting from raw material providers to finish product customers. This view helps in developing plans integrated with internal and external stakeholders. The system consists of several plants connected in series, where the output of a plant is fed to the next plant in the supply chain. These plants can be producing raw material or finished products in the petrochemical industry. The plants can also be refineries in the oil industry for any oil producing and processing company. In case of series of plants feeding each other with raw material (sub-products), a buffer or a stack of the material is maintained for continuous uninterrupted production. Final products are passed to external customers without shortage or delay. Maintenance planning for each plant draws upon different types of resources from different sources, internal and external, such as subcontractors, spare parts suppliers, and technology providers. For some highly labor intensive maintenance jobs, such as shutdown maintenance, external subcontracting is a common practice. Subcontracting major maintenance projects is a very critical issue that needs to be handled with care since external body is entrusted for major assets. Spare parts represent a significant portion of the maintenance cost. To guarantee minimum cost and highest quality and timely availability of spare parts, strong

3.1 Global Maintenance System

27

relationship with spare part suppliers is needed for best maintenance outcomes in terms of time and cost. Mutual planning and coordination is needed with technology and spare parts providers for maintaining strong relationship. Streamlining spare part acquisition, handling, and storing processing between the two organization through sales and purchasing departments is essential for a successful relationship. This relationship can be maintained with multiple providers to reduce the risk of shortage. The relationship with technology providers is a long range relationship that starts with technology acquisitions and spans the life of that technology. Quality and timely service and consultation throughout the life span of the equipment requires strong relationship and commitment from the two parties. Furthermore, feedback regarding the performance of the equipment to the technology provider helps in improving their product for a better maintainability in machine design. Strengthening this relationship and maintaining it through efficient internal and external processes and information flow is essential for the benefit of the all parties. The level of interaction with stakeholders varies with type of maintenance applied. Routine preventive maintenance activities need the least interaction with external and internal stakeholders while major shutdown project needs high level of coordination with internal and external stakeholders. Condition based maintenance requires high level of initial investment during the establishment stage and then becomes a regular activity with minimal interaction with other stakeholders. To realize the maximum benefit of the global integrated system to be integrated for serving the global objective of the corporate, several issues has be addressed and built within the system. These issues are as follows: 1. Coordination with supply chain partners. A plant undergoing a major maintenance project such as shut down maintenance, has an impact on, and impacted by, all other supply chain partners including: • • • • •

Upstream plants providing raw materials; Downstream plants using the plant products as raw materials; Vendors providing spares and long lead time items; Contractors providing manpower; and Final customers buying the plants products.

High level coordination within the supply chain helps in maximizing benefit within the whole supply chain. Coordination within the supply chain can go to a level of deciding on the timing of major maintenance activities for each plant, upstream and downstream, as well as sharing information and experiences. This coordination can be through common committees or task forces at the planning level. Mathematical models and other scientific tools may be utilized for optimizing time major maintenance activities windows and costs. Such committees might get in contact with vendors and contractors for better building strong long term relationship. Establishing such relationship with suppliers and contractors secures benefits to all parties and resolves conflicts effectively ahead of time.

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At the end of the supply chain comes the end customer that sets the requirement for the whole supply chain. Obviously that requirement is largely a major driving force for the whole supply chain. To enhance the communication process within the supply chain, an integrated information system that links all these partners together should be developed and forms the backbone for timely effective coordination. This coordination and information sharing is highly needed to secure fast response to unexpected events by other partners. 2. Performance measurement. The overall objective of maintenance is to ensure high plant safety, reliability and availability. Therefore, conducting maintenance within schedule and budget may not be enough. In addition to operational measure of budget and schedule, there is a need to emphasize and implement plant effectiveness measures. At the plant level, measures of maintenance success has to be set, monitored and utilized for future plans. Such measures should be in line with high level objectives of the organization and agreed upon at the plant level. Having similar measures across the plants within the organization helps in coordination and sharing information across different plants. Including some high level measures that impact the organization helps in optimizing maintenance at the global (system) level. Measures should be effectively utilized for improving the maintenance process at the plant level and a global level in future plans and executions. 3. Learning process and sharing of best practices with similar industries. A formal process for documenting positive and negative experiences during maintenance planning and execution should be established. The result should be shared as a best practice document that will enhance the learning process across the organization. Failing to feed back this accumulated experience to the system for future improvements is a major shortage in current maintenance practices in the industry. A plat form or a mechanism for sharing best practices across the supply chain should be established and systemized to ensure gaining the expected benefits. This learning process can be extended to other partners (suppliers, contractors and vendors) in terms of the technical know-how for design and technical specifications of equipment and spare parts. Within the organization, the maintenance department interacts with internal stakeholders at different levels, at the operational and at the business levels as shown in Fig. 3.2. Each functional unit has its own objective cascaded down from the corporate objective through a maintenance strategic plan. Production and maintenance are the most two interrelated functional areas in manufacturing organizations. While production is interested in highest level of machine utilization and delivery targets, maintenance aims to achieve highest level of long term machine readiness. There plans to achieve their target often conflict in timing creating negative interaction between the two functional units. This invites a serious effort for coordinated integrated planning process and integrated optimization tools for planning and scheduling.

3.2 Strategic Planning in Maintenance

29

Corporate

Objectives Maintenance

Production Coordination / Integration

Plan (utilization)

Equipment

Plan (availability)

Equipment condition

Fig. 3.2 Interrelation between production and maintenance

3.2 Strategic Planning in Maintenance Maintenance planning is done in three levels; strategic, medium and short term as shown in Fig. 3.3. Starting from the corporate strategic plan, the maintenance strategic plan is developed from which medium and short term plans are extracted. The focus of this Section is on the development of the strategic part of planning and it is mainly extracted from Al-Turki [2]. A strategic plan for maintenance, like any other functional plan, has to be consistent with the vision and objectives of the corporate. However, strategic planning in maintenance differs from other functional areas as follows: • The traditional view of maintenance as a cost center rather than a profit center. • The strong interconnection between maintenance and major asset management. • The high influence of maintenance on corporate objectives through asset acquisition and its management. • The nature of being highly technical and labor intensive. • The nature of key stakeholders (mostly internal). As such, strategic planning in maintenance is special in nature and has to be handled in a slightly different manner than other functional areas. The maintenance strategy is developed based on the corporate objectives and is based on a clear understanding of the role maintenance plays in the corporate strategy and on clear objectives that are in line with the corporate objectives. Strategic choices have to be made in relation to organization structure, maintenance methodologies, supporting systems and outsourcing related decisions. Once selections are made,

30

3 Integrated Maintenance Planning Maintenance strategic Maintenance Vision, Mission, Objectives

Corporate strategy Vision, Mission, objectives, strategies

Maintenance strategies (outsourcing, structure, methodologies, & support systems)

Middle range planning Forecasting, Capacity planning Goals and targets

Short term planning and scheduling

Implementation Performance Measurement System Performance Measurement

Fig. 3.3 Maintenance planning as part of the corporate planning system

middle range plans have to be made regarding capacity and workforce planning. Weekly and daily plans are then made and activities are scheduled for implementation followed by measuring performance for continuous feedback for improvement. This chapter focuses on the strategic planning portion of maintenance planning. The global view of the enterprise in relation to production and maintenance introduced by Visser [3] can be modified to reflect the partnership between the two functions in utilizing and maintaining the equipment as shown in Fig. 3.3. This view forms the base for more liberal strategic planning from the maintenance point of view that is consistent with the model introduced by Murthy et al. [4]. Both functions, production and maintenance, have to take cooperate objectives into account in their planning as well as each other’s perspectives and views regarding their own plans. While the main focus of planning is to satisfy demand by utilizing resources to the maximum, maintenance focuses on maximizing asset value and its availability. Information flowing back from operations to production and maintenance regarding equipment condition is essential in adjusting plans and also revising decisions.

3.3 The Strategic Planning Process There are different alternative methodologies for the strategic planning process. All of them stress the involvement of all stakeholders in the process using different tools such as brain storming sessions and focused group meetings. This section proposes a framework for developing a maintenance strategic plan that is based on the global view of maintenance presented in Fig. 3.3.

Corporate vision, mission and objectives

31

Maintenance Internal & external stakeholders Maintenance Mission and objectives

Benchmarking

Strategic thinking

3.3 The Strategic Planning Process

SWOT Analysis

Load & Technology

Portfolio

Strategic Issues Strategic Options Strategy Selection Performance Measures Implementation Plan Fig. 3.4 A framework for maintenance strategic planning framework

The development process is presented in the chart in Fig. 3.4. The process comprises the following steps: 1. Identify major internal and external stakeholders. Internal stakeholders include top management of the organization, other functional areas like production and inventory, other supporting functions such as IT and finance functions. Top management and production management are extremely essential in formulating the mission and objectives. The role of the labor as major stakeholders is essential in assessing the current situation and choosing strategies for different maintenance issues. 2. Formulate the mission statement. The mission statement explains the purpose of existence of maintenance in the organization and its role in achieving the vision and mission of the organization. The mission statement should clearly define the scope of work including asset identification and equipment selection,

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3 Integrated Maintenance Planning

acquisition, and management. Hence, it should be embraced and approved by top management and communicated to other parts of the organization. Mission statements reflect the focus and philosophy of the organization. The traditional focus is on quick response to breakdown, reduced down time or controlled cost. Lately, safety and environment are increasing becoming a major concern of maintenance. An example of a mission statement is ‘‘To deliver cost effective equipment availability and reliability’’. This statement gives a clear idea about the objective to be developed in the next step. Another example is ‘‘To provide excellent support for customers by reducing and eventually eliminating the need for maintenance services’’ [5]. This statement is clearly linked to a vision of the future of maintenance within the organization and it also reflects a new philosophy of being lean organization. 3. Set the strategic objectives of maintenance. The objective(s) to be formed here is the highest level measure of mission achievement that is directly linked to the overall corporate objective. Strategic objectives should be set based on the following principals: • • • •

To To To To

meet the major needs of the stakeholders based on their aspirations. improve on existing strength. overcome a major weakness or challenge. mitigate a major threat.

Stakeholders should be heavily involved in identifying the objective(s) with the corporate objective as a reference. The objective(s) should be stated in qualitative and quantitative forms. A traditional objective is to increase overall equipment reliability and/or availability that are currently viewed as challenges or threats to the overall performance of the organization in terms of its productivity and value of assets. Certain measures are adopted for each objective and targets are set based on a benchmark. 4. Analyze the current situation. The current situation means all maintenance related internal and external matters. Internal matters include strengths and weaknesses in terms of performance and its trends, current practices, available technologies, relation with other functions, and strategies and maintenance policies and practices. Duffuaa et al. [6] has developed a check list that can help in assessing the current maintenance practices. External matters include opportunities and threats. It includes competitor’s performance and practices, emerging technologies and anticipated and current government rules and regulations, emerging maintenance strategies and approaches. Several tools can be used for the analysis including: a. Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis is used to identify internal and external factors affecting the maintenance function. It identifies internal strengths and weaknesses and external opportunities and threats. This is usually done through a series of sessions with major internal and external stakeholders. SWOT also helps in identifying major issues that

3.3 The Strategic Planning Process

33

need immediate attention as well as strategic issues that need to be addressed in the long run. It also helps in seeking the desires of different stakeholders in terms of the role of maintenance and required performance. This might require a revision of the mission and objective that was set in the previous steps. This revision should be done before proceeding further in the strategic planning process. SWOT helps in understanding the key challenges facing maintenance operations. Primary and secondary data may be collected and analyzed to confirm the results of the SWOT. b. Portfolio analysis. This method is used to study trends in performance in terms of the identified objectives and existing measures of performance. c. Benchmarking is the study of the best practices in the area of maintenance in similar organizations. The focus is on performance and best practices. It is a process of identifying the best practices in the business that can be adopted for self improvement in quality and performance. This step will help in setting targets and selecting strategies at later stages of the process. The benchmarking process for maintenance quality of performance and maintenance audit is proposed by Raouf [7]. d. Load and technology analysis. This step is basically a forecasting exercise for both production load and future technologies in maintenance, production and information. This step is essential for the maintenance function since it is highly labor intensive and technology driven more than any other function in the organization. This must be conducted in partnership with the production function with the involvement of finance and Human resources. In the context of strategic planning it is used for identifying strategies and initiatives that have proven success for possible adaptation. Feeding the results of the analysis back into the mission and objectives that was previously set gives an opportunity for revisions and adjustments if necessary. So if it was too ambitious with respect to the analysis it may be brought closer to reality and vice versa. 5. Identify the strategic issues. The analysis conducted in the previous step has pointed out some issues that have a long term strategic impact. These strategic issues should be put in perspective and agreed upon with clear statements. The most common strategic issues in maintenance are identified by Murthy et al. [4] and by Tsang [8] and summarized in the literature review. 6. Strategic Options. A strategic option is an action, or a set of actions, that help to achieve a strategic objective. At this step, we analyze the strategic issues identified in the previous step and explore all possible strategies for each. The benchmarking that was conducted in the analysis is very influential in exploring alternative options in addition to the literature cited earlier. Brainstorming sessions are also useful when conducted with experts in the area. For each objective, strategic options will be developed to close the gap between the current state and the ambitions. The strategic options will be developed based upon best practices in leading organizations.

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3 Integrated Maintenance Planning

7. Strategy selection. For each strategy for each issue the pros and cons should be studied in order to make the selection that would achieve the objectives in the most efficient and effective manner. As there are several alternatives, yet feasible, ways an objective can be achieved, it is prudent to consider the option that is most attractive, effective and viable. The strategic options are evaluated against the metrics of impact, cost and resource requirement, and ease of implementation. 8. Develop performance measures. For each objective identified, develop a set of quantitative measures. There are few quantitative measures that are used in assessing the performance of the maintenance and its degree of achieving the objectives. After developing the strategic objectives the following steps will be performed: i. Operationalize every objective through specific measurable performance indicators. Parida and Kumar [9] suggest a set of performance indicators that can be helpful in this regard. ii. Assess the current status of the objectives. iii. Agree on the future ambition or level for the same objectives based upon the performance of the leading centers in date or palm research. iv. Map the gaps between the current state and the future desired ambition. Defining the performance gap contributes to an understanding of where the current system is performing in relation to the strategic objective. 9. Implementation Planning. The implementation planning step creates a framework to execute the selected strategy via a series of programs and specific recommendations. The programs will be first prioritized according to their impact and feasibility of implementation. The most important and feasible programs are further short-listed by urgency (short-term vs. long-term) and resource requirement. It is necessary to focus on a limited number of programs to ensure successful implementation. A comprehensive roadmap for implementation will be constructed. Each of the selected programs has to be defined in terms of timelines, milestones, roles and responsibilities. Organizational mechanisms to continuously monitor the entire project plan should be established. Part of the implementation plan is to develop a system for continuous assessment and strategic adjustment. The model for continuous improvement and maintenance audit introduced by Raouf [7] can be adopted for this purpose.

3.3.1 Key Success Factors The history of strategic planning cites less success than failure in implementing strategic plans due to several reasons that are mostly referring back to the development stage. However, there are a few issues that need to be taken into consideration at the development stage for higher chances of success.

3.3 The Strategic Planning Process

35

1. The support of top management. This support is not guaranteed for the maintenance as it is seldom considered as a strategic function. Therefore, unusual effort is needed for gaining their support. Awareness sessions about the role of maintenance in the core business of the organization supported by figures and analysis for key people in management helps in gaining understanding and hence the support of top management. This issue should not be taken lightly and could consume considerable time and effort. Without full and genuine support of top management results, most of the time, end in failure either in the planning process or at the implementation stage. 2. The involvement of major stakeholders is another key success factor. The absence of key stakeholders in the development process leaves some gaps in either the analysis or in evaluating strategic options. Special attention should be given to top management, production management, and operations. The alignment between maintenance with corporate strategy as well as production can be achieved by the close involvement of management at that level. 3. Ownership. The implementation plan should have an owner that controls and monitors the progress of the implementation and assess goals and target through a well developed systematic procedure. A balance score card is usually used for that purpose. 4. Strategic planning culture. Strategic planning is a culture as much as it is a process. Spreading the culture throughout the organization and maintenance management in particular is a major success factor of strategic planning. In a culture of strategic consciousness, people tend to behave and make decisions based on strategic impacts and global objectives rather than on local and short term benefits. This culture can be achieved by awareness sessions and training workshops at all levels of the organization. The strategic plan, after its development, has to be well communicated to all concerned people within the maintenance function and all stakeholders in general.

3.3.2 Strategic Issues in Maintenance Few papers have been published recently that discuss issues related to strategic maintenance planning. Tsang [8] identified four strategic dimensions (issues) of maintenance planning. The impact of the decision on these issues is long lasting and it influences other planning variables. These four issues are: 1. 2. 3. 4.

Service delivery strategy. Organization and work structure. Maintenance methodology. Support systems.

The first dimension is the service delivery strategy. Outsourcing versus in-house maintenance are two possible alternatives for maintenance delivery strategies. Many petrochemical processing plants outsource all their equipment and facility

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3 Integrated Maintenance Planning

maintenance. Others outsource particular specialized or risky aspects of maintenance. The potential benefits of outsourcing maintenance activities include less hassle, reduced total system costs, better and faster work done, exposure to outside specialists, greater flexibility to adopt new technologies and more focus on strategic asset management issues [10, 11]. Tsang [8] has an excellent analysis of the two options in terms of things that should not be outsourced. An activity that is considered to be the organization’s core competency should not be outsourced. An activity may be considered as a core competency if it has a high impact on what customers perceive as the most important service attribute or the activity that requires highly specialized knowledge and skills. The costs involved in the internal service include personnel development and infrastructure investment and managing overhead. The costs involved in the outsourcing include the costs of searching, contracting, controlling and monitoring. Murthy et al. [4] explored the outsourcing issue and discussed the long term costs and risks of different alternatives. Some general guidelines are laid out in relation to this issue including that maintenance management and planning should not be outsourced. The maintenance implementation, however, may be outsourced based on cost and risk consideration. Risks are very much linked to the service supply market. Having a single dominating supplier in the market makes the user company hostage to that supplier services. On the other hand if the suppliers are weak, they might not be able to supply quality and reliable service as much as the internal service can do. Furthermore, the service should not be outsourced if the company does not have the capability to assess or monitor the provided service and when it lacks the expertise in negotiating sound contracts. Contractual relationship with the service provider is an important aspect of outsourcing. Martin [12] studies different aspects of contracts. Contracts have to be carefully written to avoid long term escalation in its costs and risks. The benefits of outsourcing are seldom realized because of contracts that are task oriented rather than performance focused and the relationship between the service provider and the user is adversarial rather than partnering. In the absence of long term partnership between maintenance service supplier and the user, the supplier will be hesitant to invest in staff development, equipment and new technologies. The relationship between the supplier and the user is determined by the type of contract. While outsourcing has great potential for significant benefits, it also includes some potential risks such as loss of critical skills, loss of cross functional communications and loss of control over a supplier. To reduce the risks, the contract and the contracting process should be dealt with in delicate manner. Specialists in the maintenance technical requirements and specialists in technology and business needs as well as specialists in contract management should be involved in the process. The contract itself should have a conflict resolution and problem solution mechanism for uncertainties and inevitable changes in the requirements and technology changes. Other measures for reducing risks include splitting maintenance requirements into more than one supplier.

3.3 The Strategic Planning Process

37

The second dimension of strategic maintenance management identified by Tsang [8] is the organization and work structure. Traditionally, the organization structure is hierarchical and highly functionalized within which maintenance is organized into highly specialized trades. This organization has led to many problems in terms of efficiency and effectiveness. New process oriented organization structures are emerging for more effective and efficient management of business units. Within these structures, maintenance is viewed as part of a group owning the process. Different work structures may be considered for different types of maintenance work. Choices between plant flexible and plant specialized tradesman, centralized versus dispersed workshops, trade specialized versus multiskilled trade-force has to be made. The third dimension of strategic maintenance management is the maintenance methodology. There are four basic approaches to maintenance: run to failure, preventive maintenance, condition based maintenance, and design improvement. Methodologies for selecting the most suited approach such as reliability-centered maintenance and total productive maintenance are developed and adopted globally by many companies. The choice between these methodologies is a strategic decision that has to be made based on the organization’s global objectives. The fourth dimension of strategic maintenance management is the selection of the support system that includes information system, training, and performance management and reward system. Each element has to be carefully selected to support the overall objective of the organization. Enterprise Resources Planning, ERP, systems are gaining ground in large organizations and to a certain extent in medium size organizations, The power of ERP lies in its ability to integrate different functional areas within the organization which is an essential requirement for maintenance planning and scheduling. Successful implementation of the system requires careful system selection and implementation strategy that is human focused. For details about integrating maintenance strategies in ERP see Nikolopoulos et al. [13]. Managing maintenance performance has many strategic aspects that are discussed in the literature. Tsang [8] was one of the first authors linking maintenance performance to corporate strategy. He suggests a framework that uses the Balance Score Card approach for measuring performance at strategic, tactical and operational levels through the four perspectives; financial, customer, internal processes and learning and growth. He briefly discusses the process of developing a strategic plan within the context of maintenance performance management. Kutucuoglu et al. [14] introduce a more comprehensive framework for managing maintenance performance. They identified the main features of quality performance measurement system that includes vertical and cross functional integration at all levels, strategic, tactic and operational. They suggest Quality Function Deployment (QFD) methodology for building an integrated performance measurement system. Parida and Kumar [9] discuss the maintenance performance measurement system as the backbone for maintenance strategic management. They introduce the concept of total maintenance effectiveness that includes internal and external effectiveness, rather than overall equipment effectiveness. Internal effectiveness includes productivity, cost, skills and competencies, and reliability and efficiency

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of resource utilization. External effectiveness includes Customer satisfaction and growth of market share. They also make it clear that the MPM system should be based on a clear maintenance strategy that in turn should be derived from and linked to the corporate strategy. The top objectives should be cascaded into team and individual goals. They suggest a hierarchical system in which the top level addresses the corporate or strategic issues and the middle level addresses tactical issues and the lowest level addresses the operational level.

3.4 Integrated Maintenance Scheduling Maintenance scheduling is the process by which jobs are matched with resources (crafts) and assigned a time slot for execution. Duffuaa et al. [6] divides maintenance scheduling into three stages based on the time horizon of planning and implementation. The stages are: (1) Long range or master schedule to cover a period of 3 months–1 year; (2) weekly schedule, it is the maintenance work that covers a week; and (3) the daily schedule covering the work to be completed each day. Elaboration on these stages is introduced below following Duffuaa et al. [6]. The long range schedule balances long term demand for maintenance work with available manpower. Based on the long-term schedule, requirements for spare parts and material could be identified and ordered in advance. The long-range schedule is usually subjected to revisions and updating to reflect changes in plans and realized maintenance work. The weekly maintenance schedule is generated from the long range schedule and takes account of current operations schedules and economic consideration. The planner provides the schedule for the current week and the following one, taking into consideration the available backlog. The work orders that are scheduled for the current week are sequenced based on priority. Critical path analysis and integer programming are techniques that are used to generate a weekly schedule. In most small and medium sized companies, scheduling is performed based on heuristic rules and experience. The daily schedule is generated from the weekly schedule and is usually prepared the day before. This schedule is frequently interrupted to perform emergency maintenance. The established priorities are used to schedule the jobs. In some organizations the schedule is handed to the area foreman and he is given the freedom to assign the work to his crafts with the condition that he has to accomplish jobs according to the established priority. Effective scheduling plans must be supported by accurate and updated information about the overall status of equipment, spare parts, workforce, policies and procedures. More specifically the following information is necessary for sound scheduling. 1. Written work orders that explain precisely the work to be done, the methods to be followed, the crafts needed, spare parts needed and priority. 2. Time standards.

3.4 Integrated Maintenance Scheduling

39

Table 3.1 Priorities of maintenance work Code Name 1

2

3 4 5

Time frame work should start

Type of work

Emergency Work should start immediately Work that has an immediate effect on safety, environment, quality, or will shut down the operation Urgent Work should start within 24 h Work that is likely to have an impact on safety, environment, quality, or shut down the operation Normal Work should start within 48 h Work that is likely to impact the production within a week Scheduled As scheduled Preventive maintenance and routine. All programmed work Postponable Work should start when Work that does not have an immediate resources are available or at impact on safety, health, environment, shutdown period or the production operations

3. Craft availability. 4. Spare parts stocks and ordering policies. 5. The availability of special equipment and tools necessary for maintenance work. 6. The plant production schedule and its possible availability for service. 7. Well-defined priorities for the maintenance work in coordination with production. 8. Backlogs, i.e., Jobs behind schedule. Priorities are established to ensure that the most critical and needed work is scheduled first. The development of a priority system should be well coordinated with operations. Also, the priority system should be dynamic and must be updated periodically to reflect changes in operation or maintenance strategies. Priority systems typically include three to ten levels of priority. Most organizations adopt four or three level priorities. Table 3.1 provides classification of the priority level and candidate jobs to be in each class as identified by Duffuaa et al. [6].

3.4.1 Scheduling Techniques Scheduling is one of the areas that received considerable attention from researchers as well as practitioners in all types of applications including operations scheduling and project scheduling. Techniques are developed to construct optimum or near optimal schedules with respect to different possible performance measures. These techniques are shared by both production scheduling and maintenance scheduling. Some of the most common techniques for scheduling maintenance are as follows:

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3 Integrated Maintenance Planning

1. Gantt charts Gantt charts are used to visualize maintenance and production activities over a certain time horizon. The Gantt chart is a bar chart that specifies the start and finish time for each activity on a horizontal time scale. It is very useful for showing planned work activities versus accomplishments on the same time scale. It can also be used to show the inter-dependencies among jobs, and the critical jobs that need special attention and effective monitoring. There are large variations of the Gantt chart. Gantt charts can also be used to show the schedule for multiple teams or equipment simultaneously. Color codes are sometimes used to reflect certain conditions such as shortage of material or machine breakdowns. Several scheduling packages, such as Primavera, are available to construct Gantt charts for more complicated schedules involving multiple resources and large number of activities. In general, Gantt chart does not build a schedule but helps in presenting the schedule in a simple visible manner that might help in monitoring, controlling and may be adjusting schedules. Scheduling (adding new jobs to the Gantt chart) itself is done following a certain rule that is developed with experience for the schedule to perform in the desired way. An example of such a rule is loading the heaviest job to the least loaded equipment as early as possible for maximizing the utilization of the equipment. This rule is known from scheduling theory to produce a good schedule for minimizing idle time. 2. Networking Formulating the maintenance project as a network diagram helps in viewing the whole project as an integrated system. Interaction and precedence relationships can be seen easily and be evaluated in terms of their impact on other jobs. Maintenance activities commonly take the form of a project with many dependent operations forming a network of connected operations. In such cases, project management techniques can be utilized for scheduling the maintenance operations. The two primary network programming techniques used in project scheduling are the critical path method (CPM) and program evaluation and review technique (PERT). Each was developed independently during the late 1950s. The main difference between the two is that CPM uses a single estimate of activity time duration while PERT uses three estimates of time for each activity. Hence, CPM is considered to be a deterministic network method while PERT is a probabilistic method. Both networks consist of nodes representing activities and arrows indicating precedence between the activities. Alternatively, arrows may represent activities and nodes represent milestone. Both conventions are used in practice. Here we are going to use the former. The objective in both CPM and PERT is to schedule the sequence of work activities in the project and determine the total time needed to complete the project. The total time duration is the longest sequence of activities in the network (the longest path through the network diagram) and is called the critical path. Before we proceed by explaining the two methods it is worth noting that PERT

3.4 Integrated Maintenance Scheduling

41

and CPM are not well suited for day-to-day independent small jobs scheduling in a maintenance department. However, they are very useful in planning and scheduling large jobs (20 man hours or more) that consist of many activities such as machine overhauls, plant shut downs, and turnaround maintenance activities. Furthermore, a prerequisite for the application of both methods is the representation of the project as a network diagram, which shows the interdependencies and precedence relationships among the activities of the project. Maintenance activities are usually unique and commonly involve unexpected needs that make their time duration highly uncertain. CPM uses a single estimate of the time duration based on the judgment of a person. PERT, on the other hand, incorporates the uncertainty by three time estimates of the same activity to form a probabilistic description of their time requirement. Even though the three time estimates are judgmental they provide more information about the activity that can be used for probabilistic modeling. The three values are represented as follows: Oi = optimistic time, which is the time required if execution goes extremely well; Pi = pessimistic time, which is the time required under the worst conditions; and mi = most likely time, which is the time required under normal condition. The activity duration is modeled using a beta distribution with mean (l) and variance (r2) for each activity i estimated from the three points as follows: Oi þ Pi þ 4mi 6   P  Oi 2 i ^2i ¼ r 6 ^i ¼ l

Estimated means are then used to find the critical path in the same way of the CPM method. In PERT, the total time of the critical path is a random variable with a value that is unknown in advance. However, additional probabilistic analysis can be conducted regarding possible project durations based on the assumption that the total time of the project may be approximated by a normal probability distribution with mean l and variance r2 estimated as: X X ^¼ ^i and r ^2 ¼ ^2i l l r where i is the activity in the critical path. Using the above approximation we can calculate the probability with which a project can be completed in any time duration, T, using the normal distribution as follows: ^ T l PrðTcp  TÞ ¼ PrðZ  pffiffiffiffiffi Þ ¼ UðzÞ 2 ^ r where U is the distribution function of the standard normal distribution.

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Tables exist for evaluating any probability under the standard normal distribution. 4. Scheduling Using Computers It is always desirable to have a scheduling system that matches required maintenance work to available personnel and necessary equipment. The system should help maintain information of all necessary data and make them available with high reliability to build working schedules that optimizes the utilization of human resources and heavy equipment. A large number of software packages are available for optimum scheduling of personnel for planned maintenance activities and that takes into account the possibility of unplanned maintenance activities. Project scheduling packages are available to perform various functions related to project management. One of the leading packages is Microsoft Project that has the capability of maintaining data and generating Gantt charts for the projects. The critical path through the network diagram is highlighted in color to allow schedule monitoring and test alternatives. Enterprise Resource Planning (ERP) is increasingly adopted by large enterprises as a global information and data management system to integrate the information flow through various functions within, and sometimes, outside the enterprise. The maintenance function is highly influenced by other functions in the enterprise through information flow as well as strategic directions. ERP is therefore extremely useful for integrating maintenance with production, spare part inventory, and engineering and purchasing. For more details about maintenance strategy integration in ERP see Nikolopoulos et al. [13]. 5. Mathematical Modelling Optimization techniques are available in the literature for such cases and for other cases with multiple or single resource. Integer programming is commonly used for developing optimum schedules for various scheduling requirements under various problem structures. However, they turn out to be large scale models that are quite complicated for real life situations. Alternatively, heuristic methods, some of which are quite simple and practical, that results in good schedules with respect to certain performance measures. Computer simulation is heavily used in testing the performance of different competing heuristics and dispatching rules under stochastic system behavior including machine breakdowns, and stochastically dynamic maintenance job arrivals. In spite of the developments in scheduling theory, its use in maintenance scheduling is limited due to the different nature of maintenance activities compared to production activities in many aspects including: • Maintenance activities are highly uncertain in terms of duration and resource requirements; • Maintenance activities are highly related in terms of precedence relations or relative priority;

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43

• Tasks can be divided into subtasks each with different requirements; and • Tasks can be interrupted or canceled due to changes in production conditions or maintenance requirements. Recent advances in scheduling theory tended to tackle problems that are more stochastic in nature and some research is devoted to maintenance scheduling applications. Another recent trend in scheduling theory is the integration of maintenance scheduling and production scheduling which are traditionally done independently. Production scheduling focuses on allocating machine capacity to job processing, while maintenance scheduling focuses on maintaining machine capacity. These two functions are interrelated where machine interruptions cause delay in production schedules and vice versa. However, this relation seems to be overlooked in practice as well as in research. Classical production optimization models assume continuous machine availability, which might not be true in most real life manufacturing systems. A machine may become unavailable during the production process, due to Preventive Maintenance (PM), which is scheduled in advance or due to breakdowns, which occur randomly. Recently, researchers addressed the need to integrate the scheduling of both production and maintenance. Kenne et al. [15] stated that the integrated production planning and PM problem are concerned with coordinating production and maintenance operations to meet customer demand with the aim of minimizing cost. Pandey et al. [16] pointed out that production scheduling and maintenance have been treated as separate issues. In real life situations, machines do fail or need to be maintained and hence may become unavailable during certain periods. Thus, the interdependency of scheduling and maintenance has resulted in a considerable amount of interest in developing models. The motivation to integrated scheduling, in addition to cost savings, comes from the need to overcome conflicts arising between production and maintenance functions in most manufacturing systems. While the production unit has an interest in keeping a continuous production run to satisfy customer needs, the maintenance function is committed to long life asset management and optimum maintenance tasks and activities. These two objectives in many cases cause conflicts when planned or unplanned shutdowns cause serious delay in production schedules. Solving the production scheduling and PM planning problems independently ignores these inherent conflicts. Even when the conflict is managed the result is not usually optimized globally, since both schedules are developed independent from each other and then combined over the planning horizon. Modern production systems rely on optimal and effective planning and scheduling for their elements. It is a usual practice to plan for one element, independent of the others and to disregard their possible mutuality. Furthermore, this independent planning is done through separate functional teams. The resulting plans of a specific function may disrupt other function plans. For example, the maintenance function assigns a scheduled shutdown. The timing of this shutdown will be communicated to the production unit. The suggested maintenance may

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3 Integrated Maintenance Planning

Fig. 3.5 Classical planning for production. Adopted from Hadidi and Al-Turki [16]

maximize the machine availability, but will affect production plans. Similarly, production schedulers may have the tendency to utilize machines to their full capacity to meet demand. Under this condition, productivity may increase, but machine availability will decrease, due to having more breakdowns. Hadidi and Al-Turki [17] is the main source for introducing the issue of integrated scheduling in this chapter. Figure 3.5 shows the possible interactions between different elements of a production system that will be clearly visible at the shop floor level. Independent planning may provide optimal performance at the level of a specific function. Management usually looks at the production system as a whole and separate optimal solutions may not provide optimal solution for the whole system. Usually, there is a global optimal that includes all major functions in the production system. This global optimal can only be achieved by integrating models for all different functions. Integrated production models are expected to deal with multiple objectives with a conflicting nature. Hence, planning these elements independently will cause conflicts between functions. This disturbance can be minimized through coordination to include two or more elements of the production system. Figure 3.6 shows an example of scheduling in a real-life practice, where production planning is done and then that plan goes to the shop floor for implementation. Meanwhile, maintenance plans and schedules are developed and sent to the shop floor to prepare for implementation.

3.4 Integrated Maintenance Scheduling

45

Fig. 3.6 Common production planning and coordination in a real-life practice [16]

Integrated models are usually not easy to solve because of their multi-objective nature. As such, the level of integration in planning between functions is minimized. Planners may give higher priority to a certain function and plan for that solely. The output plan will be taken as an input to the second in priority function. For that function, a plan will be built taking the input of the other function as a constraint. For example, production schedules can be generated given that the machine will be out of service for a specific duration. An example of such model is developed by Cassady and Kutanoglu [18]. The model was developed for a single machine that has increasing hazard rate, i.e. subjected to failure. Each time the machine fails, it needs a fixed time to repair tr. Expected number of failures can be minimized by performing preventive maintenance before the start of the job which will restore the machine to an ‘as-good-as-new’ condition. This PM will delay the start of the job by fixed time to maintain tp, nevertheless. If the machine is required to process n jobs with the objective to minimize their expected total completion times then the scheduler is required to provide simultaneously, optimal sequence and, when to perform PM’s. To formulate the problem mathematically, a binary variable y[i] is defined where y[i] = 1 if PM is conducted and y[i] = 0 if PM is not conducted. Let P[i] be the processing time for job i. The expected completion time of job i will be, Eðc½i Þ ¼

i X k¼1

½y½k  tp þ P½k þ tr  number of failures

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3 Integrated Maintenance Planning

If each job has a given weight w[i] then the objective function would be to minimize the total weighted expected completion time represented as follows, Total Wighted Expected Completion Time ¼

n X

½wi  Eðc½i Þ

i¼1

Identifying the sequence, mathematically, can be done by introducing job assignment binary variable xij. This variable is two dimensional; one is for jobs domain i = {1, 2, . . ., n} and the other is for position domain j = {1, 2, …, n}. ( xij ¼

1 0

if job i is assigned to position j if job i is not assigned to position j

)

Two logical sets of constraints will constrain the objective function: first set of constraints states that job i can not seize two positions at the same time, i.e. n X

xij ¼ 1

8i ¼ 1; . . .; n

j¼1

The second set of constraints states that one position cannot hold more than one job, i.e. n X

xij ¼ 1

8 j ¼ 1; . . .; n

i¼1

The model is solved for the optimum production sequence. The best position for the PM with respect to the jobs in the optimum sequence is then determined. A modified version of the model is developed by Hadidi and Al-Turki [17] that combines the PM position determination is imbedded within the mathematical model. Management Methods Integrated planning can be achieved through some management tools and best practices. Some of these methods are as follows: 1. ADOPTING the right organization structure that promotes integrated planning and scheduling within different functions in the same organization is one of the possible methods. 2. Forming unified groups from related functions within the same organizations or teams from different stakeholders to plan and schedule for the whole system. 3. Training planners and schedules on integrated planning and scheduling tools and concepts. 4. Rotation is a management tool that helps in promoting global understanding of the maintenance system and its relation to other functions in the organization.

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47

5. Adopting a performance management system that includes operation, medium and high management as well as internal and external stakeholders and cross functional measures. 6. Developing a rewarding system that encourages cross functional cooperation in planning and scheduling.

3.5 Performance Measurement System Planning is not complete without a Performance Measurement System (PMS). Plans need to be coupled with a mechanism for monitoring the effectiveness of the adopted plans and their progression over time allowing for corrective actions and contingency planning. In addition, Performance measurement is highly valued in maintenance planning for measuring the value created by maintenance at the business level as well as the operational level. PMS measures the contribution of maintenance on business targets and hence helps in justifying investments on maintenance and resource allocations. An effective maintenance performance management system can lead changes in policies regarding safety and environment and in adopting new technologies and maintenance strategies. It may also lead to new management practices and changes in organizational structure. An integrated Maintenance performance measurement system should go in parallel with the integrated maintenance planning levels; strategic, medium and short term operational plans. The closest system to this requirement is the one suggested by Parida and Kumar [9] shown in Fig. 3.7. The system matches the typical hierarchical organizational management structure. The structure is composed of three levels. Top management concerned with strategic plans and decisions reflecting the corporate vision. The middle management is concerned with tactical decisions with quality, effectiveness and efficiency concerns and measures. The lower level is the functional or operational level which is mainly concerned with the maintenance process and its outcomes of that process in terms of the health of the asset. Some performance measures are identified for each level related to the planning and working objectives at that level. Objectives are cascaded down to lower levels to ensure the integration of strategies and performance and alignment of objectives. Hence, Objective at high levels are cascaded down and translated to lower level goals and objectives. Machine down time, unplanned maintenance tasks, safety and health related accidents are examples of possible performance measures at the operational or functional level. Machine availability, Production rate, production quality, and cost are examples of tactical level performance measures. These measures are directly affecting other functional areas such as production and quality. Overall equipment availability (OEE) and total maintenance cost reflect the concern of high management regarding overall maintenance performance.

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3 Integrated Maintenance Planning

OEE Cost

Availability Production rate Quality Maintenance cost

Down time Unplanned maintenance tasks Number of incidents/ accidents etc.

Fig. 3.7 Hierarchical maintenance performance levels of an organization

Each of these performance measures play a role in improving performance at a certain level and assures vertical and horizontal integration of objectives. An effective PMS should be able to link organizational effectiveness with the maintenance effectiveness reflecting the contribution of maintenance to the company business goals. The concept of total business effectiveness considers both external and internal stakeholders. External effectiveness usually linked to long term business related objectives representing satisfying customer’s needs as well as increasing market share. Internal effectiveness reflects efficiency and cost of operations, and maintenance outcome in terms of reliability of maintained resources as well as internal capabilities. Figure 3.8 gives examples of measures both internal and external effectiveness. The total effectiveness combines both in a single overall effectiveness that helps in communicating the reflection of maintenance on the overall organization performance with respect to its high level operational and strategic goals. Performance measures and performance indicators are in general used interchangeably. However, a distinction between the two helps in drawing a clearer picture of performance evaluation. Performance indicators may be viewed as tools utilized to translate performance measures into numbers reflecting the level of achievement related to that measure. One or more indicator can be used for the same performance measure. For example, customer surveys can be used as an indicator for customer satisfaction but it is not necessarily the only one. A fully integrated PMS should include various types of performance indicators. At the operational level maintenance performance indicators can be classified as leading or lagging as shown in Fig. 3.9. Leading performance indicators deal the process, such as work identification and planning and scheduling, and the

3.5 Performance Measurement System

49

Total maintenance effectiveness

External Effectiveness 1. Customer satisfying • Service quality • Timeliness of delivery • Safety 2. Growth in market share

Internal Effectiveness 1. Production 2. Cost per unit 3. Skill and competency 4. Reliability & efficiency of resource utilization

Total maintenance effectiveness = External effectiveness x Internal effectiveness

Fig. 3.8 Total business effectiveness concept

Key Maintenance Performance Indicators (KPIs)

Maintenance process/effort indicators (Leading indicators)

Work identification

% Available man hours used in proactive work Number of work order requests

Wark planning and scheduling

% scheduled man hours over total available man hours

Work execution

% WO with due date compliance %WO assigned for rework %WO in backlog MTTR

Maintenance results indicators (Lagging indicators)

Equipment affectiveness

Number of unplanned maintenance interventions Breakdown frequency MTBF Unscheduled maintenance downtime Number of shutdowns Availability OEE

Maintenance cost effectiveness

Safety and environment

% maintenance cost over replacement value % maintenance cost over sales revinue Maintenance cost per product unit

Number of safety, health and environme nt incidents

Fig. 3.9 Possible classification of performance indicators

effectiveness of the effort exerted in maintaining the equipment, such as compliance with due dates and planned budgets. Lagging measures deal with the outcomes of the maintenance process in terms of equipment health, such as equipment effectiveness and maintenance costs, and production conditions in terms of safety,

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3 Integrated Maintenance Planning

health and environment. Examples of performance indicators for each category are given in the figure. Parida et al. [19] identified seven types of performance indicators providing a balanced, hierarchical PMS for measuring the total maintenance effectiveness: 1. 2. 3. 4. 5. 6. 7.

Customer satisfaction related indicators Cost related indicators Equipment related indicators Maintenance task related indicators Learning and growth related indicators Health, safety, and environment related indicators Employee satisfaction.

These seven categories reflect the balance scorecard of Kaplan and Norton [20] that considers the tangible and intangible aspects of business in addition to the total effectiveness, external and internal. These categories of performance indicator and total productive maintenance concept can be integrated with the three level hierarchical planning systems to develop an integrated performance measurement system as shown in Table 3.2. Performance indicators that reflect the specific type of business should be selected for each of the performance measure indicated in the figure. In the following we give a list of common indicators used in practice by different industries to measure the maintenance performance.

3.5.1 Performance Indicators Traditional performance measurements focus on the simple view of the maintenance system that is composed of input, output and processes as shown in Fig. 3.10. Such view can help in surveying possible measures and indicators for a more complex system view as described in the previous section. Inputs include labor, material, spare parts, tools and equipment, contractors, as well as financial resources. Outputs include the outcomes of the maintenance function including machine and shop conditions such as availability and reliability of the maintained machine, the quality of its production as well as the safety of the working environment. Processes include planning, scheduling, controlling and the actual maintenance work execution. An exhaustive and systematic search of articles on maintenance management and maintenance performance measurement was recently conducted by Simoes et al. [21] resulted in 345 different measures and indicators mostly coming from practical applications from 32 different industries. Figure 3.11 reports the most common 37 measures. It is to be noted that cost, with 40 occurrences, was the most used maintenance performance measure (15 percent of total occurrences within this group of measures). The most utilized measures represented several

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51

Table 3.2 Multi-criteria frameworks for maintenance performance measurement [20]

Front-end process • Timely delivery • Quality • HSE issues

External Effectiveness • Customer/ stakeholders • Compliance with regulations

Hierarchical Level Level 1 Strategic

Labor Material Contracts Shop service Equipment Tool crib overhead

Operational • Production rate • Number of defects / reworks • Number of stops/downtime • Vibration & thermography • Maintenance cost

• • • • •

Cost/ finance related

• Maintenance budget • ROMI • Cost of maintenance task

• Maintenance production cost

Customer satisfaction related

Health, Safety, security and environment Back-end process • Process stability • Supply chain • HSE

Tactical

• Capacity utilization

Maintenance task related

Employee satisfaction

• Generation of a number of new ideas • Skill improvement training • Quality complaint number • Quality return • Customer Satisfaction • Customer retention • Number of accidents • Number of legal cases • HSSE Losses • HSSE complaints • Employee satisfaction • Employee complaints

Level 3

Availability OEE Production rate Quality Number of stops

Equipment/ process related

Learning growth and innovation

Internal effectiveness • Reliability • Productivity • Efficiency • Growth & Innovation

Level 2

• Quality of maintenance tasks • Planned maintenance tasks • Unplanned maintenance tasks • Generation of a number of new ideas • Skill improvement training

• Change over time • Planned maintenance task • Unplanned maintenance task

• Quality complaint number • Quality return • Customer Satisfaction • Customer new addition • Number of accidents/ incidents • Number of legal cases • Compensation paid • HSSE complaints • Employee turnover rate • Employee complaints

• Quality complaint number • Quality return • Customer Satisfaction

Maintenance Processes

Fig. 3.10 Input–output system view of a maintenance system

• Generation of a number of new ideas • Skill improvement training

• Number of accidents • Number of legal cases • HSSE • Employee absenteeism • Employee complaints

Availability Reliability Quality Equipment Value

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Fig. 3.11 The most common measures reported in the literature. Adopted from Simoes et al. [21]

dimensions of maintenance performance, namely technical, economic, safety, and human resources. To establish strong linkages between business strategy and manufacturing maintenance strategies, there is a need for a well designed and implemented

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organizational system to manage maintenance and related performance aspects from a strategic perspective. Such a system should have the following characteristics and abilities, Alsyouf [22]: • assess the contribution of the maintenance function to the strategic business objectives; • identify the weaknesses and strengths of the implemented maintenance strategy; • establish a sound foundation for a comprehensive maintenance improvement strategy using quantitative and qualitative data; • re-evaluate benchmarking maintenance practice and performance with the best practice within and outside the same industry; and • track maintenance impact and showing the linkages between operational and financial measures, holistically. The following is a list of measures commonly used in different industries some of which measure the input, some measure the outputs and some measure the ratio of output to input (productivity). Some measure efficiencies in planning, controlling or execution and some measure effectiveness in execution plans and achieving targets. The measures are at different levels, corporate, middle management (medium range) or operations (short term). Ratio of labor cost to material cost ¼

Total mainetnance labor costs Total mainetenance material cost

Cost of subcontracting maintenance % ¼

Total cost of subcontracting Direct cost of maintenance

Ratio of stock value to production equipment value ¼

Average stock value Replacement value of production equipment

Output measures may include the following: Availability ðA) ¼

scheduled time  all delays scheduled time

Reliability or Mean Time Between Failure ðMTBF) ¼

Mean Time to Repair ðMTTR) ¼

Repair down time Number of failures

Running time number of failures

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Maintainability ¼ probability(repair in a given time)

Process rate ðPR) ¼

Actual throughput rate ideal throughput rate

Quality rate ðQR) ¼

Total throughput  net rejects Total throughput

Overall equipment effectiveness ðOEE) ¼ Availability  Process rate  Quality rate

At the middle management level and maintenance processes, some possible performance indicators are: Subcontracted hours per month % ¼ Overtime hours per month % ¼ Worker activity level % ¼

Total Subcontracted hours worked  100 Total hours worked

Total overtime hours worked  100 Total hours worked

Standard hours earned  100 Total clock time

Current backlog ðin crew  weeks) ¼

Work scheduled ready to release ðin man  hours)Þ one crew  week ðin man  hours)

Total backlog ðin crew  weeks) ¼

Total labor  hours of work awaiting execution one crew  week ðin man  hours)

Worker productivity per month % ¼

Worker utilization % ¼

Standard hours  100 Total hours worked

Hoursspent on Productive work  100 Total hours scheduled for work

Composite Productivity Index ðCPI) ¼¼ Productivity  Utilization Worker Orders Planned and scheduled daily % ¼

Work orders Planned and scheduled  100 Total work orders executed

Scheduled hours versus hours worked as scheduled % ¼

Hours worked as scheduled  100 Total scheduled hours

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55

Hours scheduled Total hours worked Preventive and predective maintenance conducted as scheduled % Total manhoursof preventive and predective maintenance executed  100 ¼ Total manhoursof preventive and predectivemainetnance scheduled Preventive and predective maintenance coverage Total man hours of preventive and predective mainetnance ¼  100 Total man hours worked Scheduled hours versus hours worked % ¼

Cost per unit ¼

total maintenance cost Total units produced

Cost of mainetenance to added value of production % ¼

Direct cost of maintenance  100 Added value of production

Direct maintenance costs include manpower, material, and cost of subcontracted work and overloads. The added value of production is the cost of production less the cost of material. Examples of high level (corporate level) maintenance performance indicators include the following: Maintenance cost relative to sales % ¼

$ Total maintenance cost  100 $ Total sales

Maintenance cost relative to production volume = Maintenance cost relative to investment % ¼

Budgeting plans effectiveness = Effectiveness of execution =

$ Total maintenance cost Total volume produced

$ Total maintenance cost  100 $ Total investment on plant equipment

$ Total maintenance cost  100 $ Total budgeted maintenance plans

Number of planned jobs completed by due date Total number of planned jobs

Effectiveness of material managemnt =

Number of planned jobs awaiting for material Total number of planned jobs

These maintenance performance measures are usually used as appropriate to the business sector at the appropriate level of command. The data are collected and compared with historical data to reflect trends in performance and benchmarked with best in the industry. Data base systems are usually used for collecting and analyzing data for performance improvement. The measures help in recognizing and improvement or guiding for improvement. Various information systems are available for supporting data collection, recording and analysis of performance

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indicators some of which are integrated with other functional areas, such as ERP systems. While cost is an important measure, future research should also focus on deriving practical performance measures aimed at capturing the human factor of the maintenance performance effort. The study by Simoes et al. [21] showed that the least utilized measures included training/learning, skills/competences, work incentives, process performance, resources utilization, maintenance capacity, customer satisfaction, employee satisfaction. Furthermore, future research should attempt to integrate the findings from the case studies into practical implementations methodologies. The characteristics of the industry should be examined in attempt to conceptualize industry specific factors in relation to effective maintenance performance.

References 1. Al-Turki UM, Duffuaa S, Bendaya M (2013) A holistic system approach for turnaround performance management, maintenance performance measurement and management, MPMM 2013, Lappeenranta, Finland, 2013 2. Al-Turki UM (2011) A framework for strategic planning in maintenance. J Qual Maintenance Eng 17(2):150–162 3. Visser JK (1998) Modeling maintenance performance: a practical approach. In: IMA conference, Edinburgh, pp 1–13 4. Murthy DNP, Atrens A, Eccleston JA (2002) Strategic maintenance management. J Qual Maintenance Eng 8(4):287–305 5. Levitt J (2010) Death of the maintenance department and what you can do about it. http:// www.maintenanceresources.com/referencelibrary/maintenancemanagement/death_of_the_ maintenance_dept.htm, Jan 2010 6. Duffuaa SO, Raouf A, Campbell JD (1999) Planning and control of maintenance systems: modeling and analysis. Wiley, New York 7. Raouf A (2009) Maintenance quality and environmental performance improvement. In: BenDaya M, Duffuaa SO, Raouf et al A (eds) Handbook of maintenance management and engineering. Springer, London, pp 649–664 8. Tsang AHC (1998) A strategic approach to managing maintenance performance. J Qual Maintenance Eng 4(2):87–94 9. Parida A, Kumar U (2009) Maintenance productivity and performance measurement. In: Ben-Daya M, Duffuaa SO, Raouf et al A (eds) Handbook of maintenance management and engineering. Springer, London, pp 17–41 10. Watson P (1998) Performance specified maintenance contracts—why it is better for a client to specify desired results rather than how to achieve them. In: Proceedings of the 3rd international conference of maintenance societies, Adelaide, Australia, Paper 2, pp 1–9 11. Campbell JD (1955) Outsourcing in maintenance management: a valid alternative to self provision. J Qual Maintenance Eng 1(3):18–24 12. Martin HH (1977) Contracting out maintenance and a plan for future research. J Qual Maintenance Eng 3(2):81–90 13. Nikolopoulos K, Metaxiotis K, Lekatis N, Assimakopoulos V (2003) Integrating industrial maintenance strategy into ERP. Ind Manage Data Syst 103(3):184–191 14. Kutucuoglu KY, Hamali J, Irani Z, Sharp JM (2001) A framework for managing maintenance using performance measurement systems. Int J Oper Prod Manage 21(1/2):173–194

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15. Kenne J, Gharbi A, Najid N (2009) On the integrated production, inventory and preventive maintenance problem in manufacturing systems with back-order. Int J Simul Process Model 5(4):300–312 16. Pandey D, Kulkarni M, Vrat P (2010) Consideration of production scheduling, maintenance and quality policies: a review and conceptual framework. Int J Adv Oper Manage 2(1/2):1–24 17. Hadidi LA, Al-Turki UM (2012) Integrated models in production planning and scheduling, maintenance and quality: a review. Int J Ind Syst Eng 10(1):21–50 18. Cassady RC, Kutanoglu E (2005) Integrating preventive maintenance planning and production scheduling for a single machine. IEEE Trans Reliab 24(2):304–309 19. Parida A, Chattopadhyay G, Kumar U (2005) Multi-criteria maintenance performance measurement: a conceptual model. I: Proceedings of the 18th international congress COMADEM, 31st Aug–2nd Sep 2005, Cranfield, UK, pp 349–356 20. Kaplan RS, Norton DP (1992) The balanced scorecard—measures that drive performance. Harv Bus Rev 70:71–79 21. Simoes JM, Gomesm CF, Yasin MM (2011) Maintenance performance measurement: a conceptual framework and directions for future research’’. J Qual Maintenance Eng 17(2):116–137 22. Alsyouf I (2006) Measuring maintenance performance using a balanced scorecard approach. J Qual Maintenance Eng 12(2):133–149

Chapter 4

Health, Safety and Sustainability in Maintenance

Abstract Maintenance is one of the key issues for retaining values of assets and achieving the desired performance. However, maintenance is also a major element in providing and maintaining a safe and healthy working environment for the people within the manufacturing facility and in its neighborhood. Ill-maintained asset, machinery, or structure is a potential source of serious health problems and accidents. In this chapter, health and safety issues related to the maintenance itself and to its impact on the work environment are presented in the manufacturing setting. Keyword Health and safety Maintenance safety



Sustainable maintenance



Safety measures



Maintenance is very well recognized for its role in retaining assets’ value and performance as originally intended in terms of quality, productivity, reliability, and safety. There is no doubt that an ill maintained asset, machinery or civil structure, is a potential source of serious health problems and accidents. Studies show an inverse relationship between injury frequency index and maintenance audit score. Some studies estimated that around 40 % of serious accidents in industries are related to maintenance. Maintenance itself is a high-risk activity that can be a major source of health and occupational hazards for workers and people present in the workplace, if not performed with appropriate safety measures. It was estimated that 80 % of accidents related to maintenance occur during the maintenance phase and 20 % during regular operation. Data from the Spanish working conditions survey indicate a higher exposure of maintenance workers to noise, vibrations and different kinds of radiation when compared to the rest of the working population (see Fig. 4.1). As soon as machine is commissioned it starts to deteriorate and without proper maintenance it runs into a dangerous state of wear, tear, fatigue, and corrosion and then breakdown. Most accidents occur just before, during or after maintenance. Maintenance concepts such as, TPM and RBM, and strategies, such as preventive maintenance and condition based maintenance, focus on minimizing and controlling breakdowns and hence improving safety. U. M. Al-Turki et al., Integrated Maintenance Planning in Manufacturing Systems, SpringerBriefs in Manufacturing and Surface Engineering, DOI: 10.1007/978-3-319-06290-7_4,  The Author(s) 2014

59

60 Fig. 4.1 Exposure to hazards among maintenance workers (Spain 2007)

4 Health, Safety and Sustainability in Maintenance 30 25 20 15 10 5 lazer

Other workers Ionizing

Microwaves

Radiofrequencies

UV light

infrared light

hand arm viberations

loud noise

very loud noise

whole body…

Maintenance workers

0

Maintenance impacts the occupational safety and health of workers in two dimensions. First, correctly planned and carried out maintenance is essential to keep machines and the work environment safe and healthy. The effect of maintenance may in many cases extend to the general public and the global environment. Second, maintenance itself has to be planned and performed in a way that insures the safety of maintenance workers and other people present in the workplace during maintenance operations. Poorly planning and/or performed maintenance can cause deadly accidents and health problems to workers and may be extended to the public. Safety in relation to maintenance can be discussed in two dimensions. First, the impact of maintenance on maintaining a safe and health work environment (maintenance for safety), and second, the safety of the maintenance activity itself (maintenance safety).

4.1 Maintenance and Safety Maintenance involves a wide range of activities, such as inspection, testing, measuring, adjustment, cleaning, etc., performed by variety of occupations, such as mechanics, electricians, building caretakers, etc. As such, risks associated with maintenance are numerous. Maintenance work in manufacturing involves, in addition to the risks associated with any working environment, some specific risks. These include: • Manufacturing technology is quite complicated that makes it difficult to understand, operate, and maintain. • Maintenance is highly pressurized in time and cost by production and business requirements. • Maintenance is usually conducted alongside a running process and in close contact with machinery. • Maintenance is in many cases is subcontracted and hence involves workers who might not be familiar with the machinery and the place.

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61

• Maintenance often involves Non-routine tasks and exceptional conditions. • Maintenance involves direct contact between the worker and machine that cannot be reduced substantially. • Maintenance may be required without prior notice for proper preparation. As a result of these risks, maintenance is associated with all kinds of accidents. Occupational accidents during maintenance work are numerous. Approximately 50 % more accidents happen during maintenance work than during normal production. These accidents often result in severe injuries and prolonged time off work. Maintenance workers are not only at risk of being involved in a work-related accident, but also of developing occupational diseases. As a result, the hazards to which maintenance workers are exposed vary depending on the task and the working sector. Hazards include physical, chemical, and psychosocial hazards. Chronic exposure to certain hazards may cause health problems such as asbestosis, cancers, hearing problems, skin diseases, respiratory diseases, musculoskeletal disorders with, as a consequence, a higher-than-usual sickness absence rate. Studies indicate that industrial maintenance workers might be at especially high risk of occupational diseases. According to a French study, industrial maintenance employees have a rate of occupational diseases 8–10 times greater than the average population. A high percentage of reported cases of musculoskeletal disorders occur in maintenance workers—mechanics, electricians. Many accidents are related to work equipment and machine maintenance, e.g. crushing by moving machinery, unexpected start-up. Other accidents involve falls from height, accidents involving falling objects, Electrocution, electrical shocks, burns, confined spaces, asphyxiation, Explosion, and fire. Maintenance workers are frequently exposed to excessive noise caused by machinery, equipment or by vehicles. Long term exposure to high sound levels causes several undesirable effects on the health of operators, causing hearing problems such as hearing loss or tinnitus, and non-auditory problems such as difficulties in concentrating, sleeping disorders, gastric ulcers, and increased blood pressure. Workers performing maintenance tasks might also be exposed to vibrations. Exposure to hand-arm vibration occurs when hand-held power tools, such as grinding, polishing are used, or riveting tools, percussion hammers, vibrating compactors, mowers or chain saws are used. These tools can transmit vibrations to the worker’s hand causing vascular, neurological and musculoskeletal disorders such as white finger syndrome, a decrease in the sense of touch, and elbow arthritis. Workers are also exposed to vibrations caused by heavy machinery when a large part of the body rests on a vibrating surface. This is the case for drivers of commercial vehicles, such as tractors and fork-lift trucks. Maintenance workers in some industries are exposed to uncomfortable or extreme environmental conditions. They can be exposed to high or low temperatures, to excessive humidity, to poor ventilation or to UV radiation or radiant heat sources. Arc welders, for example, are exposed to ultraviolet and visible light from the electric arc.

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Maintenance workers are sometimes subjected to ergonomic hazards. They might be required to lift heavy loads that may not be within easy reach, access may be poor or there may not be sufficient space to move. Floors may be slippery or cables might be in the way. Workers performing maintenance tasks can be exposed to repetitive movements, such as turning many screws by hand or with poorly designed tools. Sometimes workers have to hold tools or parts of the installation they are working on in place for some time and this can lead to significant static muscular workload and local muscle fatigue. Workers can be exposed to chemical hazards during maintenance work where chemical substances can be released into the working environment by the task being carried out and the worker may come in contact with them. Some of these hazards are: • Inhalation of chemicals (gases such as CO, H2S, SO2, various fumes and vapors, lack of oxygen in confined spaces, i.e. typically an excess of N2 or CO2). • Direct exposure through the skin (caused by splashes, contaminated surfaces, etc.) • Physical effects (burns due to chemical fires or hot substances, injuries caused by pressure waves, e.g. as a consequence of explosions, impact by fragments caused by explosions, etc.) • Workers might be exposed to chemical hazards for example, during electric arc welding, while working in industrial installations where hazardous chemicals are present. • Specific maintenance operations may involve risks associated with asbestos fibers during maintenance of industrial installations and buildings where asbestos is present in the structure. Exposure to chemical hazards leads to diverse and sometimes severe health problems. Asbestosis, skin diseases, and respiratory diseases, cancer are just a few examples. Maintenance workers may experience stress caused by the nature maintenance itself such as, time and cost pressure, complex technology combined with nonroutine situations, working alone and in isolation, irregular working hours, and insufficient knowledge about building lay-out or the machines they have to use or to maintain.

4.1.1 Maintenance for Safety Machine deterioration starts immediately after commissioning the machine and starting operations and that is when the role of maintenance starts. Lack of maintenance or inadequate maintenance can lead to dangerous situations, accidents and health problems. Maintenance failures may contribute to large-scale disasters with extremely damaging consequences for humans and the environment. On the other hand, maintenance itself can be a source of increased failure risks and thus unnecessary maintenance is not desirable. Therefore, choosing an appropriate

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63

maintenance strategy and its frequency in addition to quality implementation is essential for occupational safety and health. Maintenance involves, lubricating, cleaning, moving, replacement of deteriorating parts, and assembly and disassembly of machines. Each activity if not done properly may result in machine failure either immediately during restarting or after short or long term of operation. Some sources of hazard risks that results from maintenance are: • • • •

Spilled or leaking lubricants Using wrong or low quality spare parts Wrong reassembly of machine Not replacing a deteriorated part during maintenance.

Some of these are human errors and some are poor management. Human errors may happen because of lack of training or information, fatigue, lack of motivation, time or cost pressure, lack of support, and lack of mental or physical ability. Good planning, management and controlling in addition to workforce training supported by the right tools and equipment reduces these sources of risks. The process of maintenance should start at the design and planning stage— before maintenance workers even enter the workplace. It is essential to implement appropriate risk assessment procedures for maintenance operations, as well as employing adequate preventive measures to ensure the safety and health of workers involved in maintenance activities. After maintenance operations are completed, special checks (inspections and tests) should be carried out to ensure that maintenance has been properly carried out and that new risks have not been created. During the whole process good maintenance management should ensure that maintenance is coordinated, scheduled and performed correctly as planned, and that the equipment or workplace is left in a safe condition for continued operation. Maintenances strategies, concepts and integrated approaches such as TPM and RCM (introduced in the previous chapter) influences safety and health at work in several ways. • • • • • •

Reduces the risk of unplanned maintenance and sudden breakdowns Integrates of OSH management into maintenance management Helps manage health and safety in a structured way Assures adequate risk assessment Ensures training and competence Involves workers in the risk assessment and maintenance management process.

Many typical risks in maintenance operations involve proper design for maintainability of machines that impacts safety: • • • •

easy access to the components to be maintained minimizing the number of components to be replaced, connected, disconnected increasing maintenance intervals making difficult or impossible to perform a maintenance task incorrectly or in an unsafe way.

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4.1.2 Methods for Maintenance Safety Improvement There are four approaches to industrial hazard avoidance [1]: • • • •

Analytical approach Engineering approach Enforcement approach Psychological approach.

The last two approaches deals with human error related to all kind of behaviors in all types of environments. The first two are more specifically relevant to operations and maintenance. Analytical Approach deals with hazards by analyzing their mechanism and analyzing historical data. Some of the common analytical approaches are: • Accident root cause analysis • Failure mode and effect analysis • Fault tree analysis. More information about these approaches is available in traditional maintenance textbooks. The engineering approach utilizes three major tools for reducing safety hazards in the workplace. • Engineering controls • Safety procedures for maintenance work • Personal protective equipment. Engineering controls focus on designing and redesigning tools, machines and equipment by feeding back their safety performance to improve designs. It also introduces protective instruments and controls for safe fails and shutoffs and for protecting plants against release of toxic material or over pressurization. The design and selection of Personal protective Equipment (PPE) for different working environments and types of hazards is a third engineering approach. PPEs are designed for personnel protection against potential occupational accidents and diseases. Among the most important are • • • •

Hand, head, foot, and eye protective equipment Hearing protective equipment Respiratory Protection equipment Body protection.

4.1 Maintenance and Safety

65 Safety Performance Indicators

Reactive Indicators

Proactive Indicators

Predictive/Monitoring

Safety deviations Near Misses Behavioral indicators Accident free periods Audit score Safety attitude Organization risk factor

Safety Effort Indicators

No. of safety audit/inspections Safety budget Hours of training per worker Hours of Mgt. time spent No. of risk assessment

Accident rate Lost rime injury rate Medical treatment cases Accident cost Severity rate No. of leaks No. of Fires First aid rate

Fig. 4.2 Example of maintenance performance indicators

4.1.3 Safety Measurement Safety improvement effort must be directed by some performance measurement system that includes; safety indicators, inspection, data collection, analysis and corrective action. Maintenance can utilize such systems for monitoring and improving its performance in terms of safety. An example of such performance indicators is shown in Fig. 4.2 in which indicators are classified as proactive and reactive. Accident rate and lost time injury rate are two examples of reactive indicators. Examples of safety effort indicators include number of safety audits and safety budgets. Near-misses is an example of monitoring and behavioral indicators is an example of predictive indicators.

4.1.4 Safety Legislations Safety legislations are developed by several organizations that include standard procedures and standards for safe workplace including maintenance. Some of these agencies are: • Occupational Safety and Health Act of 1970 (OSHA act) is developed to protect worker and work place safety. The OSHA act was enacted through the Occupational Safety and Health Administration agency of the US department of

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4 Health, Safety and Sustainability in Maintenance

labor. Another organization that is actively involved in occupational safety and health legislation is the international Labor Organization. • The European Agency for safety and Health at Work is the European agency concerned with occupational safety regulations. • The European Framework Directive 89/391/EEC introduced measures to encourage improvements in the safety and health of workers. • Romec, an organization in the UK offering maintenance services, has developed a comprehensive health and safety management system that complies with the British Occupational Health and Safety Assessment Series (OHSAS) 18,001 Standard. This system contains safety procedures, safe systems of work and around 400 generic risk assessments covering all products and routine tasks within the business.

4.2 Maintenance and Sustainability The concept of sustainability is increasingly gaining importance in all aspects of modern civil life development including energy, food, transportation, and manufacturing. Sustainable development is defined by the United Nations World Commission on Environment (UNWECD) as ‘‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs’’. It has three pillars; economy, society and environment, as illustrated in Fig. 4.3 using three overlapping ellipses indicating that the three pillars of sustainability are not mutually exclusive and can be mutually reinforcing, suggesting that both economy and society are constrained by environmental limits. http://en.wikipedia.org/wiki/Sustainability#cite_note-15, access date: 2014. With this global effect of sustainable development the manufacturing sector is moving from traditional manufacturing to lean manufacturing (reducing waste), to green manufacturing (reducing waste, reusing and recycling) and lately to sustainable manufacturing. Sustainable manufacturing is defined by the U.S. Department of Commerce as ‘‘the creation of manufactured products that use the processes that minimize negative environment impacts, conserve energy and natural resources, are safe for employees, communities, and consumers and are economically sound.’’ Sustainable manufacturing utilizes the 6R innovation elements (Reduce, Reuse, Recycle, Recover, Redesign, and Remanufacturing). Sustainable manufacturing utilizes the 6R innovation elements (Reduce, Reuse, Recycle, Recover, Redesign, and Remanufacturing). http://www.trade.gov/competitiveness/sustainablemanufacturing/how_doc_ defines_SM.asp [2]. Figure 4.4 illustrates the closed loop manufacturing system that uses the 6R innovation system in comparison with the open loop traditional system. The 6R includes the recover, redesign and remanufacture of products or components in addition to reducing waste and energy, and reusing and recycling of products and components.

4.2 Maintenance and Sustainability

67

Fig. 4.3 A diagram indicating the relationship between the three pillars of sustainability

Economy Society Environment

Fig. 4.4 Closed loop product life cycle system. Adapted from [2]

Manufacturing

Use Reuse Recover

Remanufacture Material processing

Retirement Reduce

Material extraction

Energy

Recycle

Redesign

Raw material

Treatment & Disposal

Waste

Emissions

Earth

Manufacturing processes sustainability deals with assets and operations. Manufacturing assets impact cost, power consumption, waste, health, safety, and environment resulting from manufacturing operations and logistics. Environment is affected by toxic emissions, waste production, and waste of energy, scrap and rework. Maintenance as the custodian of assets plays a major role in manufacturing process sustainability.

4.2.1 Sustainable Maintenance Maintenance, being a major role player in manufacturing and asset management, is becoming under special attention for its role in sustainable business development. Since the concept of sustainable development is rooted in the systems thinking concept of understanding ourselves and our world, it is advisable to use the maintenance system concept that was introduced in Chap. 3 for planning for sustainability. In that system, maintenance is viewed as a part of a complex network of multiple organizations integrated vertically and horizontally to improve

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production quality, reduce waste, increase safety, while improving the quality of life, environment, and society in the long run. This view locates maintenance in the heart of the system from a manufacturing perspective. Commissioning life of manufacturing assets may be divided into three stages: 1. Procurement and installation stage 2. Operational stage 3. Decommissioning stage. Adopted from Liyanage et al. [3]. At the procurement stage maintenance should be heavily involved in the technology selection processes to insure safety, maintainability and long term sustainability. Some of maintenance activities at this stage are listed below: • Maintenance scenarios to manage future threats and opportunities • Defining maintenance related design basis to set acceptable standards for functional integrity • Identify and define feasible maintenance work philosophies and programs • Technical quality compliance strategy for third party systems and equipment suppliers • Execution of risk and vulnerability analyses (including reliability, hazard and operability, maintainability and supportability, etc.) • Goal setting and responsibility charting • Document compliance and development procedures • Competence mapping and development procedures • Development of work process • Damage proof storage and logistic solutions. Ill maintained chemical or desalination plants have more toxic emissions than well-maintained ones during operations. Cleaning material used for maintenance operations can produce toxic waste if not selected and used carefully. Monitoring, controlling, and eliminating all sources of health, safety, and environmental hazards should be a major part of maintenance plans. Some of maintenance things to do for sustainable performance of assets are listed below: • • • • •

Technical condition optimization with respect to plant performance target Continuous revision and update of maintenance philosophies and programs Continuous update and effective management of technical documentation Continuous integrity analysis and review of life cycle costs Analysis of performance trends and historical losses to map operational risk exposure • Competence revisions and managements • Audits and verifications of inspection, testing, and maintenance activities • Continuous criticality analysis and work priority setting.

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Some maintenance activities at the decommissioning stage are listed below: • • • •

Integrity and remaining useful life analysis Condition assessment and reusability analysis in the new operating set-up Assessment of risk exposure Removal and reinstallation planning.

In general, integrated maintenance planning processes described in Chap. 3 puts maintenance in line with the e-organizational strategic setting. Sustainability, being a global strategic issue, brings up the role of maintenance as a custodian of manufacturing assets sustainability.

4.3 Conclusion Maintenance is one of the most important factors for maintaining safe and healthy work environment in manufacturing sector. Maintenance may contribute positively or negatively on the safety of the work place. Maintenance work itself is one of the highest risk types of work for various reasons including time pressure and lack of training. Types and Sources of hazards during and after the maintenance work are numerous including human errors and poor management. Several international organizations took the mission of guiding the industry for ensuring safe environment and safe maintenance procedures. Governments and legislative organization regulates and enforce standards for ensuring the safety in the working environment. The issue of sustainable development has become global concern in all aspects of life including manufacturing. Being the custodian of the manufacturing assets, maintenance planning for sustainability is as important as its planning for asset availability, reliability and safety.

References 1. Baston RG (1999) How preventive maintenance impacts plant safety. In: Proceedings of annual conference on maintenance and reliability, Gatlinburg TN, Maintenance Reliability Center, University of Tenessee 2. Jayal AD, Badurdeen F, Dillon OW Jr, Jawahir IS (2010) Sustainable manufacturing: Modeling and optimization challenges at the product, process and system levels. CIRP J Manufact Sci Technol 2:144–152 3. Ben-Daya M, Duffuaa SO, Raouf A, Knezevic J, Ait-Kadi D, Liyanage JP, Badurdeen F, Ratnayake C (2009) Industrial asset maintenance and sustainability performance. In:Handbook of maintenance management and engineering. Springer, Berlin, pp 665–693

Chapter 5

Ethics in Maintenance

Abstract Ethical principles are essential for developing a sustainable success at the business level as well as at the individual level. This applies to all professions including maintenance engineering. Unethical acts in maintenance can lead to disastrous incidents and develops an unhealthy working environment. Professional organizations put in place codes of ethics that should be followed by all members of the professions. In this chapter, ethical issues, concerns, and codes of conducts related to the maintenance profession are discussed. Keyword Maintenance ethic

 Codes of conduct  Professional values

Business or professional ethics examines ethical principles and moral or ethical problems that arise in a working environment. It applies to all aspects of professional conduct and is relevant to the conduct of individuals and entire organizations. Ethical issues include the rights and duties between a professional individual and his fellow workers, the organization and its employees, suppliers, customers and neighbors, the public at large and the global environment. The National Society of Professional Engineers (NSPE) has developed and published the engineering code of ethics [1]. Other specific engineering professional societies, such as mechanical and civil engineering, have also developed their own code of ethics, that does not vary much in their fundamental principles. The American society of civil engineers has developed the code of ethics for Civil engineers with seven canons: 1. Engineers shall hold paramount the safety, health and welfare of the public and shall strive to comply with the principles of sustainable development in the performance of their professional duties. 2. Engineers shall perform services only in areas of their competence. 3. Engineers shall issue public statements only in an objective and truthful manner. 4. Engineers shall act in professional matters for each employer or client as faithful agents or trustees, and shall avoid conflicts of interest. U. M. Al-Turki et al., Integrated Maintenance Planning in Manufacturing Systems, SpringerBriefs in Manufacturing and Surface Engineering, DOI: 10.1007/978-3-319-06290-7_5,  The Author(s) 2014

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5. Engineers shall build their professional reputation on the merit of their services and shall not compete unfairly with others. 6. Engineers shall act in such a manner as to uphold and enhance the honor, integrity, and dignity of the engineering profession and shall act with zerotolerance for bribery, fraud, and corruption. 7. Engineers shall continue their professional development throughout their careers, and shall provide opportunities for the professional development of those engineers under their supervision. Each of the canons is supported by detailed practicing guidelines. Maintenance professional have no specific code of ethics and thus fall under the general engineering code of ethics.

5.1 Maintenance Code of Ethics People in the workplace as well as business owners put their trust on maintenance staff to maintain a safe and healthy working environment and restoring the value of their assets. It is expected that maintenance is done with the highest level of professional values, ethics and attitudes. It is expected that they will always do the ‘‘right’’ thing when it comes to ensuring safe and productive operations. Professional values, ethics and attitudes are the professional behavior and characteristics that identify maintenance professionals. They include the ethical principles of conduct considered essential in defining the distinctive characteristics of professional behavior, that include: a commitment to technical competence; ethical behavior (such as independence, objectivity, confidentiality and integrity); professional manner (such as due care, timeliness, courteousness, respect, responsibility and reliability); pursuit of excellence (such as commitment to continuous improvement and life-long learning) and social responsibility (such as awareness and consideration of the public interest). The Professional Aviation Maintenance Association (PAMA) has identified key ethical principles stated as follows: 1. 2. 3. 4. 5. 6.

The Principle of Respect—Treat others as you want to be treated. The Principle of Non-Malevolence—Do no harm with your actions. The Principle of Benevolence—Act to promote the well-being of others. The Principle of Integrity—Conduct yourself professionally. The Principle of Justice—Treat people fairly. The Principle of Utility—Choose the actions that promote the greatest good for the greatest number of people. 7. The Principle of Double Effect—Choose actions so the good effects are greater than the bad effects. Maintenance Codes of ethics are developed by associations in different sectors and they usually have a common factor that encompasses all maintenance professionals. The Professional Aviation Maintenance Association (PAMA) has published the

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Code of Ethics for Maintenance Personnel. The Aircraft Engineers International organization has also published a Code of Professionalism. Some of the key elements common to these codes are as follows: • Maintenance professionals are responsible to the general public. • Maintenance professionals are expected to maintain currency of knowledge, exercise truth, integrity and honesty in their judgment, and work within the scope of their expertise. • Maintenance professionals are expected to remain loyal to the general public and refrain from for compromising safety for personal gains. • Maintenance professionals are expected to exercise assertiveness and not allow any superior to pressure him/her to approve aircraft or equipment as airworthy under questionable circumstances. Ethics check lists are usually developed and used as a tool for self-assessment and quality assurance. An example from the aviation industry that applies to almost all maintenance professionals is shown below.

5.1.1 Pre-task Checklist • • • • • • • •

Do I have the knowledge to perform the task? Do I have the technical data to perform the task? Have I performed the task previously? Do I have the proper tools and equipment to perform the task? Am I mentally prepared to perform the job task? Am I physically prepared to perform the task? Have I taken the proper safety precautions to perform the task? Have I researched the FARs to ensure compliance?

5.1.2 Post-task Checklist • • • • • • • • •

Did I perform the job task to the best of my abilities? Was the job task performed to be equal to the original? Was the job task performed in accordance with appropriate data? Did I use all the methods, techniques, and practices acceptable to the industry? Did I perform the job task without pressures, stress, and distractions? Did I re-inspect my work or have someone inspect my work before return to service? Did I make the proper record of entries for the work performed? Did I perform the operational checks after the work was completed? Am I willing to sign on the bottom line for the work performed?

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Examples of the most essential ethical and professional conduct associated with maintenance are cited below: • Reporting data and information related to machine performance accurately. Failure to do that for any reason might lead to wrong plans and decisions resulting financial loss and/or safety and health risks. • Conducting failure and accident investigation professionally and honestly. Failure to do so increase the risk of reoccurrence with more severe consequences. • Attempting to perform unfamiliar tasks without seeking help or proper training. A technician or engineer doing this put himself and his coworkers in risk of serious and may be fatal accident. • Management putting pressure on maintenance professional to reduce maintenance time for the sake of increasing production is an ethical misconduct that might expose worker in the plant for different types of hazards. • Purchasing low quality spare parts for the sake of reducing maintenance cost contributes to loss value of machines and more seriously causes sudden breakdowns and becoming a source of health and physical hazard for maintenance workers and machine operators.

5.2 Conclusion Professional societies are concerned with ethical conduct as much they are concerned with professional development. Such societies put in place an agreed upon code of ethics for their members to abide with. Engineering societies such as civil engineers, mechanical engineers and chemical engineers, have developed and published their code of ethics. Business and management societies also have their own code of ethics. Maintenance professionals need to have a widely acceptable code of ethics governing their professional conduct, attitudes and commitment toward their organization success as well as society and global sustainability.

Reference 1. http://www.nspe.org/resources/ethics/code-ethics

Chapter 6

Recent and Future Trends in Maintenance

Abstract Maintenance is globally important to sustain equipment, process, and measures. It has also multidisciplinary features combining almost all engineering fields, mathematics, statistics, information sciences, and management. In this chapter, recent developments and future trends in maintenance in relation to all the above fields are briefly presented. Keyword Recent developments

 Future trends  Engineering fields

Maintenance is a multidisciplinary area where Engineering, mechanical and electronic, information, telecommunication and networking technologies, mathematical, statistical, and management areas integrate for the advancement in maintenance management and engineering. Any development in one or more of these areas will create a chain reaction in the other areas for improved maintenance integration. Development in instrumentation technology, for example, changes the type, amount, timing and accuracy of collected data which triggers a change in the way big data are analyzed and affect the decision making processes. This flow of data calls for improved decision support system development and drives changes in management structure and practices. Recent advances in telecommunication and internet applications caused the emergence if the e-maintenance concept and advancement in instrumentation and control led to prognostic tools for better condition based maintenance e-systems that are integrated with e-maintenance leading an efficient e-maintenance system. More work is expected in the future for the development of intelligent maintenance system that utilizes advancements in electronic measurement devices, remote sensing for more efficient communication and controlling of processes. In addition, planning for maintenance at strategic as well operational level will adapt to the intelligent maintenance systems. This technical development will also create a stream of mathematical tools for optimizing resources in view of the technology uses and costs with traditional constrains relaxed and new cost parameters opening for improved solutions of different maintenance policies.

U. M. Al-Turki et al., Integrated Maintenance Planning in Manufacturing Systems, SpringerBriefs in Manufacturing and Surface Engineering, DOI: 10.1007/978-3-319-06290-7_6,  The Author(s) 2014

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New trends in integrated planning started to generate a new look at maintenance concepts such as TPM and RCM from a global perspective that involves internal and external stakeholders at the business level rather than a functional level. This integrated planning will allow maintenance to cope with global sustainability issues and other legislative issues. Integrated planning will help in transforming maintenance into a value added activity rather than a cost center with minimum contribution to the objective of the organization. Future will have more effective use of recent trends in supply chain management for mitigating costs and risks amongst business partners in the supply chain. Adopting the management methods and optimization tools that have proven success in other business areas will drive a new stream of efficient and effective use of resources in maintenance.