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• Sheryll Pascobillo

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WORK STUDY REVIEWER 1. A work sampling study was conducted on a particular machine and the result is provided in the tally sheet below: No. of Observations 28

Running Idle Broken 6 Out of stock 11 Others 5 At 95% confidence level, the machine is expected to run between __________% and _________ % of an 8-hour work-shift. Round off final answers to 2 decimal places. A. 42.24% & 64.31% B. 42.24% & 69.76%

C. 41.34% & 67.48% D. 40.27% & 63.86%

2. A time study was performed on a particular machine, the results of which are as follows: Mean manual effort time per cycle : 6.53 minutes Mean cutting time (power feed) : 4.36 minutes Mean performance rating: 115% Machine allowance (power feed) : 10% Fatigue allowance: 15% Compute the standard time for the operation. Round off final answer to 2 decimal places. A. 12.13 mins B. 11.33 mins

C. 13.43 mins D. 14.42 mins

3. A manual operation has been introduced in the plant and subsequently its standard time is determined to be 0.2 min. A new operator was assigned to the operation and it took him 0.4 minutes to the make the 1 st unit. The 16th unit took him 0.3 minutes to make. Working at this rate, how long will it take (in minutes) for the operator to reach the standard time? Round off final answer to 1 decimal place. A. 177.7 minutes B. 176.4 minutes

C. 174.3 minutes D. 178.7 minutes

4. What is another name for Time Study? A. Ergonomics B. Work Measurement

C. Methods Engineering D. Work Design

5. A worker is shoveling sand at a rate of 8 kcal/min. How much rest does he need during an 8-hour shift? How should the rest be allocated? Round off your answer to 3 decimal places. A. 3.104 B. 3.018

C. 3.321 D. 3.202

6. What is the combined noise level of two sounds of 86 and 96 dB? Round off final answer to 1 decimal place. A. 80.34 dB B. 96.40 dB

C. 88.57 dB D. 94.36 dB

7. A study reveals that a group of three semiautomatic machines assigned to one operator operates unattended 80 percent of the time. Operator service time at irregular intervals averages 30 percent of the time on these three machines. What would be the estimated machine hours lost per eight-hour day because of lack of an operator? Round off answers to 3 decimal places. A. 1.684 hours B. 1.285 hours

C. 1.944 hours D. 1.257 hours

8. The following data were collected by an intern working at the Mole Hill Ski Resort regarding the efficiency of the V-8 Ford engine that was used to power the rope tow for the bunny slope. Management would like to know how many hours of service they can expect to achieve out of their obviously failing engine out of a

typical 16 hour skiing day. After studying the data, you can state with 95% confidence that the engine will be able to run for ________ hours ± _________ hours of a 16 hour day. Running on 8 cylinders

IIIII

Running on 7 cylinders

IIIII IIIII II

Running on 6 cylinders

IIIII IIIII IIIII II

Not running, engine clogged

IIIII IIIII IIIII IIIII IIIII II

Round off your answers to two (2) decimal places. A. 8.83 ± 1.89 B. 8.72 ± 1.79

C. 8.92 ± 1.99 D. 8.64 ± 1.39

9. The analyst in the Dorben Company wishes to assign a number of similar facilities to an operator, based on minimizing the cost per unit of output. A detailed study of the facilities reveals the following:

Loading machine standard time Unloading machine standard time Walk time between two machines Operator rate Machine rate (both idle and working) Power feed time

= 0.34 minute = 0.26 minute = 0.06 minute = $12.00 per hour = $18.00 per hour = 1.48 minutes

How many of these machines should be assigned to each operator? Round off final answer to whole number. A. 1 B. 2

C. 3 D. 4

10. In the Dorben Company, a materials handling operation in the warehouse is being done by hand labor. Annual disbursements for this labor and for related expenses (social security, accident insurance, and other fringe benefits) are $8,200. The methods analyst is considering a proposal to build certain equipment to reduce this labor cost. The first cost of this equipment will be $15,000. It is estimated that the equipment will reduce annual disbursements for labor and labor extras to $3,300. Annual payments for power, maintenance, and property taxes plus insurance are estimated to be $400, $1,100, $300, respectively. The need for this particular operation is anticipated to continue for 10 years. Because the equipment is specially designed for the particular purpose, it will have no salvage value. It is assumed that the annual disbursements for labor, power, and maintenance will be uniform throughout the 10 years. The minimum rate of return before taxes is 10 percent. Based on an annual cost comparison, should the

company proceed with the new material handling equipment? Show complete solution for justification. 11. Who are the founders of the motion study technique? 12. The machining time per piece is 0.164 hours and the machine loading time is 0.038 hours. With an operator rate of $12.80 per hour and a machine rate of $14 per hour, calculate the optimum number of machines for lowest cost per unit of output. A. $3.46 B. $3.27

C. $3.35 D. $3.18

13. What proportion of machine time would be lost in operating four machines when the machine operates 70 percent of the time unattended and the operator attention time at irregular intervals averages 30 percent? Is this the best arrangement on the basis of minimizing the proportion of machine time lost? 14. An ergonomist suggests replacing two mail clerks, each of whom sorts 3,000 pieces/h and gets paid $10 per hour, with a machine vision system that can sort 6,000 pieces/h but costs $1 per hour to maintain and $50,000 to purchase. How many hours would it take to pay off the system? Round off your final answer to 1 decimal point A. 2,541.5 hours B. 2,631.6 hours

C. 2,538.4 hours D. 2,742.7 hours

15. Given the following operations and unit times in minutes (#1 = 1.5, #2 = 3, #3 = 1, #4 = 2, #5 = 4), balance the production line with the goal of producing 30 units/hr.

1 2

3 A. 6 stations

4

5 B. 5 stations

C. 4 stations

D. 3 stations

16. What basic motion generally precedes ‘reach’? A. Grip B. Hold

C. Release D. Follow

17. What is control movement without system response known as? A. Deadair B. Deadspace

C. Idle D. Rest

18. True or False. According to the present OSHA law, two hours of a 100 dBA sound level would be permissible in an 8-hour shift. 19. What is WBGT? A. Wet Bill Global Technique B. Wet Bulb Globe Temperature

C. Wait Browse Ground Train D. Wet Bulb Global Temperature

20. What is the WBGT with a dry-bulb temperature of 80 oF, a wet-bulb temperature of 70oF, and a globe temperature of 100oF? Assuming indoor conditions with no solar load. A. 77oF B. 75oF

C. 79oF D. 74oF

21. What is the combined noise level of two sounds of 86 and 96 decibels? A. 94.3 dB B. 95.4 dB

C. 96.4 dB D. 97.3 dB

22. What is the contrast created by black text (reflectance=10%) on white paper (reflectance=90%)? A. 0.75 B. 0.79

C. 0.85 D. 0.89

23. True or False. Poor standards mean that some are too ‘tight’ and other are too ‘loose’. Those operators with tight standards will complain and cause problems. Operators with loose standards will not be working atthe true standard and the company will loose money. 24. True or False. Under the Westinghouse rating system, Conditions, such as temperature, humidity, etc., are evaluated because if they are different from what is normally found at the workstation, operator performance will be affected. 25. What fatigue allowance should be given to a job if it developed that it took 1.542 minutes to perform the operation at the end of continuous work and but 1.480 minutes at the beginning of continuous work? 26. In an assembly process involving six distinct operations, it is necessary to produce 250 units per eight-hour day. The measured operation times are as follows: a. 7.56 minutes. b. 4.25 minutes. c. 12.11 minutes

d. 1.58 minutes. e. 3.72 minutes. f. 8.44 minutes.

How many operators would be required at 80 percent efficiency? How many operators will be utilized at each of the six operations? 27. A current problem in the U.S. Army is the neck/shoulder fatigue experienced by helicopter pilots. To be able to fly missions at night, the pilots wear night vision goggles, which are attached to the front of the helmet. Unfortunately, these are fairly heavy, causing a large downward torque of the head, which must be counteracted by the neck muscles, which then fatigue. To alleviate this problem, many pilots have started attaching random lead weights to the back of the helmet. Find the appropriate weight that would best balance the head and minimize neck fatigue. Assumptions: a) cg of goggles is 8 inches in front of neck pivot point, b) goggles weigh 2 lbs., c) max volitional neck torque is 480 in lbs., d) cg of lead weight is 5 inches behind neck pivot point, e) bare helmet weighs 4 lbs., and f) cg of helmet is 0.5 inches in front of neck pivot. A. 4.21 B. 3.82

C. 4.08 D. 3.60

28. How much capital could be invested in a new method if it is estimated that $5,000 would be saved the first year, $10,000 the second year, and $3,000 the third year? Management expects a 30 percent return on invested capital. A. $11,128 B. $12,134

C. $10,149 D. $11,218

29. The following data resulted from a time study taken on a horizontal milling machine: Mean manual effort time per cycle: 4.62 minutes. Mean cutting time (power feed): 3.74 minutes. Mean performance rating: 115% Machine allowance (power feed): 10 percent. Fatigue allowance: 15 percent. What is the standard time for the operation? A. 10.248 mins B. 10.128 mins

C. 10.224 mins D. 10.254 mins

30. A work measurement analyst in the Dorben Company took 10 observations of a high-production job. He performance rated each cycle and then computed the mean normal time for each element. The element with the greatest dispersion had a mean of 0.30 minutes and a standard deviation of 0.03 minutes. If it is desirable to have sampled data within ±5 percent of the true data, how many observations should this time study analyst take of this operation? A. 26 cycles B. 27 cycles

C. 28 cycles D. 29 cycles

31. Establish the money rate per hundred pieces from the following data: Cycle time (averaged measured time): 1.23 minutes Base rate: $8.60 per hour. Pieces per cycle: 4. Machine time (power feed): 0.52 minutes per cycle. Allowance: 17 percent on effort time; 12 percent on power feed time. Performance rating: 88%

A. $4.7047 B. $4.3817

C. $4.6874 D. $4.8047

32. Express the standard of 5.761 minutes in hours per hundred pieces. What would the operator's efficiency be if 92 pieces were completed during a working day? What would his efficiency be if he set up his machine (standard for setup = 0.45 hours) and produced 80 pieces during the eight-hour workday? 33. How long would it take to turn 6 inches of 1-inch bar stock on a No. 3 W. & S. turret lathe running at 300 feet per minute and feeding at the rate of 0.005 inch per revolution? A. 1.025 B. 1.054

C. 1.047 D. 1.042

34. The Dorben Company is using the work sampling technique to establish standards in its typing pool section. This pool has varied responsibilities, including typing from tape recordings, filing, Kardex posting, and copying. The pool has six typists who work a 40-hour week. Seventeen hundred random observations were made over a four-week period. During the period, the typists produced 9.001 pages of routine typing. Of the random observations, 1,225 showed that typing was taking place. Assuming a 20 percent allowance and an adjusted performance rating factor of 0.85, calculate the hourly standard per page of typing. A. 0.07489 hrs/page B. 0.07524 hrs/page

C. 0.07844 hrs/page D. 0.07962 hrs/page

35. The Dorben Company is designing a cast-iron part whose strength T is a known function of the carbon content C, where: T=2C 2+¾C-C3+k. To maximize strength, what carbon content should be specified? A. C = 1.6% carbon content B. C = 1.7% carbon content

C. C = 1.5% carbon content D. C = 1.3% carbon content

36. What would be the required number of readings if the analyst wanted to be 87 percent confident that the mean observed time was within ±5 percent of the true mean and he established the following values for an element after observing 19 cycles: 0.09, 0.08, 0.10, 0.12, 0.09, 0.08, 0.09, 0.12, 0.11, 0.12, 0.09, 0.10, 0.12, 0.10, 0.08, 0.09, 0.10, 0.12, 0.09?

A. 22 B. 21

C. 24 D. 23

37. The following data resulted from a study taken on a horizontal milling machine: Pieces produced per cycle: 8. Average measured cycle time: 8.36 minutes. Average measured effort time per cycle: 4.62 minutes. Average rapid traverse time: 0.08 minutes. Average cutting time power feed: 3.66 minutes. Performance rating: 115 percent. Allowance (machine time): 10 percent. Allowance (manual time): 15 percent. The operator works on the job a full eight-hour day and produces 380 pieces. How many standard hours does the operator earn? What is her efficiency for the eight-hour day? A. B. C. D.

8.484 hours; 100.5 % 8.094 hours; 101.2 % 8.104 hours; 98.3 % 8.534 hours; 97.5 %

38. Operators assemble pumps at an hourly rate of $10.00. The standard time for the assembly is 20 minutes. Direct material costs are $19.50/pump. Indirect labor and other overhead is calculated simply at a rate of $5.00/hr, while general office expenses are calculated at a rate of $2.00/hr. What is the factory cost for one pump? A. $25.17 B. $24.58

C. $23.16 D. $26.47

39. Workers new to carburetor assembly take 15 minutes to complete their first assembly. Assuming a 95% learning curve, how long would it take them to reach a standard time of 10 minutes? A. 23.22 hours B. 25.69 hours

C. 27.48 hours D. 28.75 hours