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Six Sigma

Subjects : certifications, six-sigma, business-skills

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. What is a Pareto chart?
5%
Outside.
No -- only if the process is also capable.
A descending order-sorted bar chart with a cumulative percentage line.

2. Approximately what percent of a normal distribution falls between ± 2 standard deviations from the mean?
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
Can't tell without a Range chart.
95%
Define - measure - analyze - improve - control.

3. Define perceived quality (Garvin's framework).
Brand image.
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
The Japanese national quality award.
No -- if it is not the same - it can only be worse!

4. DFMEA
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
68%
To obtain a certain desirable outcome from the process
Initiated before or at design concept finalization

5. Regression Analysis
It's good -- but it's still out of control!
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Technique used to relate through a model - one or more independent variables and a dependent variable (response)
The gap between what management thinks customers want and the process specifications.

6. What is process capability?
The ability of a process to consistently meet customer specifications.
Upper control limit.
= y = Beta(0) + Beta(1)X + epsilon y=dependent variable (response) x=independent variable (predictor of y) - epsilon=error component - Beta(not)=intersection. If data include zero - it represents the mean of the distribution of y when - x=0. It does
False - because each machine will have different natural tolerances.

7. What is poka yoke?
Mistake-proofing.
False - because each machine will have different natural tolerances.
It looks to minimize the probability of a failure - or to minimize its effects
Different types of defects are listed (used for Pareto chart)

8. Uses of regression
Different types of defects are listed (used for Pareto chart)
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
No -- only if the process is also capable.
Kaoru Ishikawa.

9. Approximately what percent of a normal distribution falls between ± 3 standard deviations from the mean?
Scrap - rework - retest - downtime - yield losses - disposition costs.
Organize ideas into meaningful categories by recognizing their underlying similarity
99.73%
3.4 (assuming 1.5 sigma shift in the mean)

10. Cause and Effect Diagrams
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Before production starts
Method developed by Ishikawa to graphically display the causes of any given problem
Technique used to relate through a model - one or more independent variables and a dependent variable (response)

11. Affinity Diagrams
Studying firms with the best performance in a particular area.
Blame.
10 if Almost impossible to detect
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions

12. Presence of interaction effect
A systemized group of activities designed to 1. recognize and evaluate the potential failure of product/process and its effects 2. Identify actions which could eliminate or reduce the chance of potential failure ocurring 3. document the process
X-bar-bar
Rapid improvement process.
If the Response vs. Levels graph if the response lines are not parallel (crossing)

13. Test for constant variance
Critical to quality.
Plot the residuals vs. the fitted values (mean of each group - y(hat) = y (bar)i ) - Assumption of ____________not rejected if the dispersion of every group is approximately the same.
Deming.
The number of standard deviations some value is from the mean.

14. What is an affinity diagram?
How likely it is to have an F statistic of that value if there really is no relationship between the dependent variable and the independent variable(s).
The manager in charge of a process being improved in a Six Sigma project.
A brainstorming tool that shows the connections between ideas.
A time series plot.

15. What is Type II Error?
Upper control limit.
Scrap - rework - retest - downtime - yield losses - disposition costs.
Concluding there has not been an effect/change when there has.
Producer risk.

16. A process is operating "in control." Does this mean the customer's requirements are met?
The ability of a process to consistently meet customer specifications.
No -- only if the process is also capable.
95%
It usually isn't possible to hold all other variables constant - There is no way to account for the effect of joint variation of independent variables - such as interaction - There is no way to account for experimental error - including measurement v

17. If your process is capable at two sigma - what percentage of the output will you have to inspect to find defectives?
100%
5%
The secondary characteristics of a product; "bells and whistles."
Variable.

18. For what is an x-bar chart used?
To monitor a process when measurement by variables is used.
3.4 (assuming 1.5 sigma shift in the mean)
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.

19. What is Type 1 Error?
Concluding there has been an effect/change when there has not.
Hold all input variables constant except one. Observe the response as you vary the single input.
Sort - Set in Order - Shine - Standardize - Sustain
Is what induces the failure

20. With Six Sigma capability - how many defects per million opportunities would you see?
1) Identify the Range (Max Value - Min Value) 2) Determine # of bins 3) Determine the Width of each bin --> (Range / # Bins) 4) Put values in correct Bin
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
3.4 (assuming 1.5 sigma shift in the mean)
Inventory = throughput x flow time.

21. What are the 5 Ss?
It looks to minimize the probability of a failure - or to minimize its effects
Sort - Set in Order - Shine - Standardize - Sustain
Kaoru Ishikawa.
Technique used to relate through a model - one or more independent variables and a dependent variable (response)

22. TWO-DIMENTIONAL SCATTER PLOT
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
To manage the Six Sigma project.
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables

23. In a regression - what does R-square tell you?
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Variable.
Causes that lead to a particular effect.
Stratify a particular defect type according to logical criteria

24. What size should samples be for attribute SPC?
Deming.
Large enough to find two of the attribute - on average.
Shifts - Trends - Repeating patterns - Correlation with known events
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.

25. Manual Test for Nomality
Concluding there has not been an effect/change when there has.
Mean time to failure.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.

26. What is the Baldrige Award?
The US national quality award.
Reliability - Assurance - Responsiveness - Tangibles - Empathy
An assertion or conjecture concerning one or more populations
F_alpha - df(tr) - df (error)

27. Define benchmarking.
Studying firms with the best performance in a particular area.
No -- only if the process is also capable.
Mean time to replacement.
consists of plotting the residuals vs. the order of each experiment - If - as in the case of the constant variance a random horizontal band is obtained - the ______________ of the residuals is not rejected. (should be random above a below the line i

28. Statistical Hypothesis
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
An assertion or conjecture concerning one or more populations
Controlling quality at the source.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper

29. What does SIPOC stand for?
Prevention and appraisal costs are balanced against internal and external failure.
A tool that shows where there is waste in a process.
Supplier - input - process - output - customer.
Prevention - appraisal - internal failure - external failure.

30. List Garvin's eight dimensions of product quality.
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
To be a member of a Six Sigma project team.
Variable.
Method developed by Ishikawa to graphically display the causes of any given problem

31. In the Service Quality Gap Model - what is Gap 2?
The gap between what management thinks customers want and the process specifications.
Represents the behavior of a process
A descending order-sorted bar chart with a cumulative percentage line.
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"

32. What is a run chart?
A time series plot.
The gap between specifications and how service is performed.
Before production starts
The primary operating characteristics of a product.

33. Creating a Run Chart
No -- the variation also has to be random and "expected."
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
A descending order-sorted bar chart with a cumulative percentage line.
Financial - customer - internal process - innovation and learning.

34. Does it ever make sense to accept a job when a process is incapable?
5%
A random variable that summarizes the information from the sample(s).
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

35. For what is a p-chart used?
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
To monitor a process when measurement by attribute is used.

36. Defect check sheets
Concluding there has been an effect/change when there has not.
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
Organize ideas into meaningful categories by recognizing their underlying similarity
Different types of defects are listed (used for Pareto chart)

37. What graphical tool is used to show the relationship between two numerical variables?
A scatterplot.
95%
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed

38. What does a project prioritization matrix do?
Critical to quality.
Upper control limit.
The gap between what is promised and what is delivered.
Assigns scores to weighted criteria for each project under consideration.

39. Design of Experiments (DOE) approach
It usually isn't possible to hold all other variables constant - There is no way to account for the effect of joint variation of independent variables - such as interaction - There is no way to account for experimental error - including measurement v
The cycle time required to meet demand.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
To monitor a process when measurement by attribute is used.

40. What is the center line of a p-chart?
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.
3.4 (assuming 1.5 sigma shift in the mean)
p-bar - the long-run percent defective.
It's good -- but it's still out of control!

41. What is CTQ?
Critical to quality.
Plot the residuals vs. the fitted values (mean of each group - y(hat) = y (bar)i ) - Assumption of ____________not rejected if the dispersion of every group is approximately the same.
Large enough to find two of the attribute - on average.
A random variable that summarizes the information from the sample(s).

42. Based on what principal can we use the normal distribution assumptions for SPC?
Central Limit Theorem
Fitness for use.
Define - measure - analyze - design - verify.
Brand image.

43. If a Cp shows that a process is not capable - should you calculate Cpk?
Is what induces the failure
No -- if it is not the same - it can only be worse!
consists of plotting the residuals vs. the order of each experiment - If - as in the case of the constant variance a random horizontal band is obtained - the ______________ of the residuals is not rejected. (should be random above a below the line i
Initiated before or at design concept finalization

44. One factor at a time (OFAT)
False - because each machine will have different natural tolerances.
Observed variation in response is caused by the input
Decomposing the total variation of data into: (a) the internal or "natural" or "within" groups variation - and (b) the "between" groups variation in such a way that when these two types of variation are compared - it's possible to determine if there
Prediction and estimation. based on an unknown x value - estimation is based on a known x value

45. What do you do when a process is out of control?
Look for the assignable cause of non-random variation.
Variable.
Define - measure - analyze - improve - control.
99.73%

46. What are the four regression assumptions?
Organize ideas into meaningful categories by recognizing their underlying similarity
consists of plotting the residuals vs. the order of each experiment - If - as in the case of the constant variance a random horizontal band is obtained - the ______________ of the residuals is not rejected. (should be random above a below the line i
Variable.
Linearity - normality - homoscedasticity - independence.

47. The Test Statistic (TS)
Fewer good units to sell - increased variable cost/unit.
A brainstorming tool that shows the connections between ideas.
A random variable that summarizes the information from the sample(s).
Because the mean and standard deviation are independent of each other.

48. What is the difference between the way sampling is done for SPC and for acceptance sampling?
Sampling for SPC is done real time.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
Lower control limit.
Through producer/consumer negotiation.

49. What is the center line of an X-bar chart?
Shifts - Trends - Repeating patterns - Correlation with known events
X-bar-bar
Define - measure - analyze - improve - control.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

50. If you can only collect categorical data - what type of SPC charting can you do?
Is the way in which the failure is manifested.
The House of Quality.
Attribute.
A tool that shows the physical flows through a space.