• Author / Uploaded
• Kefin Tajeb

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Green Belt Exam 1 Why is it important to have a strategy when first starting a project? A. It is impressive to discuss strategy with management. B. Improve project completion efficiency. Tactics without strategy wastes time. C. It will greatly improve the measurement systems analysis 2 What is the meaning of the equation A = S + R A. Ppk requirement is 1.33 or less for long term data. B. Focus on the gauge error. C. All of it equals some of it plus the rest of it. Use the graph below to answer questions 3-6

3 What does the 0.42 seconds represent? A. The b intercept – point where the line crosses the y axis at x=0. B. The slope of the line. C. Some of it (variation explained by KPIV). D. Rest of it – (variation due to other factors) 4 What does the “0.0113 sec/mm X Wing Length” represent? A. The b intercept – point where the line crosses the y axis. B. The slope of the line C. Some of it (Variation explained by KPIV). D. Rest of it – (variation due to other factors) 5 What does 0.0113 sec/mm represent? A. The b intercept – point where the line crosses the y axis. B. The slope of the line. C. Some of it (Variation explained by KPIV) D. The Rest of it – (variation due to gauge error or other factors)

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6 What does +/- 0.085” represent? A). The b intercept – point where the line crosses the y axis. B). Slope of the line. C). Some of it (variation explained by KPIV). D). Rest of it – (other factors). 7 A team has an issue with oil leaks in the vehicle. They search under the hood and find an oil cooler leaking. They notice the oil is coming out between a shaft and a seal. They tear the oil cooler apart and find nicks on a shaft. A walk of the process of shaft manufacturing uncovers a gauge fixture that is creating the nicks. What problem solving strategy did the team use to find the cause of the leaks? A). Working backwards from Y to X. B). Transfer function physics. C). Contrast and convergence. D). Acceleration to degradation and or failure. E). Stress strength interference. 8 A process for manufacturing door trim panels has rejects for a profile greater than 0.01”. The lower the profile dimension, the better the panels fit to the door. The team decided to select 3 samples from each of the ends of the distribution to study differences. What strategy did the team choose?

A). B). C). D). E).

Working backwards from Y to X. Transfer function physics. Contrast and convergence. Acceleration to degradation and or failure. Stress Strength Interference.

9 A weld breaks during assembly. What method is appropriate for solving this issue? A). Working backwards from Y to X. B). Transfer function physics. C). Contrast and convergence. D). Acceleration or degradation E). Stress strength interference. 10 A headlight has 0.01% fallout for weld failure in the vehicle. The team creates a test to apply increasing pressure until the weld fails. Which strategy is the team using? A). Working backwards from Y to X. B). Transfer function physics. C). Contrast and convergence. D). Acceleration to degradation and or failure. E) . Stress strength interference

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11 The new Super Duty truck is having transmission gear failures. The investigation team found that a new gear material was being used. The team measured the stress applied to the gears versus the strength of the new material (see graph below). What is the strategy?

Gear

A). Working backwards from Y to X. B). Transfer function physics. C). Contrast and convergence. D). Acceleration or degradation. E). Stress strength interference 12 Two CNC machines are used to make wheel hubs. Is there a significant difference in the median diameter of the hubs built by each machine?

A). End count is 7 but there are not enough samples to prove a significance. B). End count is 7 and there is a significant difference C). End count is 4 but there is not enough data to prove significance D). End count is 3 but there is not enough data to prove significance 13 Team is having an issue with plastic welds breaking. There are two welding machines used to make the parts. The team believes that welder #1 makes stronger parts than #2. Correct?

A). Yes – the end count is > to 7 so welder #1 is making stronger parts. B). No – Not enough data to prove significance. C). No – the end count is > 7 but welder #2 is making the stronger parts. D). No – the end count is not > 7 which is not enough to prove significance.

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14 A bearing inside a fan motor is making an objectionable noise causing customer complaints. The team decides to test new bearing grease by Kluber and compare it to the current Krytox grease. Is Kluber grease a significant improvement?

A). B). C). D).

Yes – The average noise level of the Kluber appears to be less than the Krytox. No – The data sets have complete overlap so the end count is much < 7. Yes – Kluber Grease has parts that are less than the Krytox Grease parts. No – The Tukey end count is only 4, fail to reject the null.

15 Why are operational definitions important when setting up a measurement system? A). Operational definitions are for use in the military, not by greenbelts. B). So everyone clearly understands exactly how measurements should be taken. C). To improve the design of a part. 16 What is the difference between repeatability and reproducibility gauge error A). Repeatability is the deviation part-to-part by one operator. Reproducibility is the deviation in measurements between operators. B). Reproducibility is the deviation part-to-part by one operator and repeatability is the deviation in measurements between operators. 17 “A” and “B” show variation from the same process. What is the difference? A). Process “A” represents gauge error and “B” is the process variation. B). “A” and “B” are the same. C). “A” is short term variation while “B” is long term.

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18 Two flow charts shown below are for the same process. Which one is better for problem solving?

A). Flow chart A is simpler to use and more easily understood. B). Flow chart B is more detailed which helps the team understand variation sources. C). Both are good so just pick your favorite.

19 Two measurements systems were evaluated for use on problem solving. Which of the following two measurement systems would you use? Gauge 1

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20 A machining process is making some gears that are too short and some that are too long. Four machines manufacture the gears and each has four spindles to make the parts. How should the team design the checksheet to stratify the data. A). Just measure all of the data off the end of line to understand the total variation. B). Record the machine vendor name. C). Does not matter. D). Record machine number and spindle for each part. 21 The team is working to reduce scrap on a molding process (see graph below). Should they complete a Design of Experments (DOE) to determine the KPIV (s)? A). Yes – DOE is the best method for determining KPIVs. B). Maybe – Only if there are enough people to run experiments. C). No –DOE is a last resort D). No – Process is not stable. Need to determine the special cause(s) driving the out of control condition. Fix the special cause before attempting a DOE.

22 A team completes a study of cavity pressure and time a gate valve is open versus the height of a part. Is there an interaction between pressure and gate valve time?

A). There is no interaction B). No – lines are close to parallel so there is no interaction. C). Probably – Lines are not parallel indicating a likely interaction.

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23. What is the Tukey end count for cavity pressure at 2500 psi? A). 8 – complete seperation (Significant) B). 0 – completed overlap (Not significant) C). 4 – (Not significant) 24. What is the Tukey end count for cavity pressure at 3100 psi? A). 8 – complete seperation (Significant) B). 0 – completed overlap (Not significant) C). 4 – (Not significant) 25 A Designed Experiment main effects plots are shown below. Which variables appear to have the biggest influence on the pressure at which the part leaks?

A). All factors are significant with slope and significant effect B). Need to see the MSA. C). Depends upon the shift and other environmental conditions. D). Surface Finish is not significant. Lacing and Coating are significant..

.

Use the problem solving model below to answer question

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26 The team has a problem with plastic welds breaking and is analyzing weld strength vs. potential KPIVs. Per step “A” of the problem solving model shown above what type if issue is this? A). Geometry B). Physics

27 Team is working to mean center a body panel stamping. What is the issue? A). Geometry B). Physics

28. A machining process sometimes gets a metal chip between the chuck and the part causing the part to have an out of specification runout. What type of issue is this? A). Geometry B). Physics 29 Which of the following tactics exemplify step “B” (The physics of how a product or process is supposed to work) ? A). Team reviews detailed process flow chart and decides temperature and pressure might be critical variables. A DOE for molding height is completed and results in the following equation: Molding height = 52 + 0.25*temperature + 0.45*pressure + 0.05*weld temperature*pressure. B). Team implements SPC to continue to control the process. They observe out of control points and investigate. 100% inspection is put in place anytime the process is shown to be out of control. C). Should be based on what experts say is important.

30 A). B). C). D).

The two key principles of 6-Sigma are: Predictability first followed by Variation Reduction. Statistical tools and Designed Experiments. Statistical Thinking and Physics. Cultural Change and Systems Thinking.

31 Statistical Thinking recognizes that everything is a process, all processes vary, and reducing key variation is the path to process success. A). True. B). False.

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32 A). B). C). D).

What percentage of the time is a single KPIV in control of a single KPOV? 30 to 50%. 50 to 70% 0%, there are always more than one KPIV. 80 to 100%, single factors heavily dominate.

33 Physics is more important than statistics: A). True. B). False. 34 Identify the following descriptions as CTQ, CTQ Error State, KPOV, or KPIV factors: Description 2 Psi to Leak I like my Engine 50 Micron Gap 100 R/1000

Factor KPOV CTS KPIV CTS error state

35 The team theorizes that going to a Mexican restaurant takes longer than other local restaurants (see data below). Is the team’s theory statistically significant?

A). B). C). D).

No – it takes that long anywhere. Maybe – Not enough data. No - End count is less than 7. Yes – End count is > 7.

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