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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. FMEA
Is the consequence of the failure.
Mistake-proofing.
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
Lower control limit.

2. One factor at a time (OFAT)
Observed variation in response is caused by the input
Look for the assignable cause of non-random variation.
The US national quality award.
Rapid improvement process.

3. For your SPC sample you weigh bags of potatoes. Is this variable or attribute SPC?
Variable.
Is the consequence of the failure.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
= yij - y(bar)i --> value minus sum of that treatment (of row)

4. Stratified defect check sheets
Stratify a particular defect type according to logical criteria
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables
Pleasing to the senses.
A scatterplot.

5. Simple Regression Analysis (one factor regression model)
A tool that shows performance along key dimensions all at once.
No -- the variation also has to be random and "expected."
= 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
The cycle time required to meet demand.

6. What is Kaizen?
Sort - Set in Order - Shine - Standardize - Sustain
Fractional factorial designs (orthogonal arrays)
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
Rapid improvement process.

7. What are the four regression assumptions?
Before production starts
Conformance to specifications.
Mean time to failure.
Linearity - normality - homoscedasticity - independence.

8. Who first studied randomness in industrial processes
The secondary characteristics of a product; "bells and whistles."
68%
Walter A. Shewhart
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.

9. Define product reliability.
Mean time to failure.
Represents the behavior of a process
If the Response vs. Levels graph if the response lines are not parallel (crossing)
Linearity - normality - homoscedasticity - independence.

10. What are two other names for an Ishikawa diagram?
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
To obtain a certain desirable outcome from the process
Fishbone - cause-and-effect diagram.
10 for Hazardous without warning 1 for none

11. What size should samples be for attribute SPC?
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Failure Modes and Effects Analysis
Large enough to find two of the attribute - on average.
Upper control limit.

12. For what is a p-chart used?
To monitor a process when measurement by attribute is used.
Technical quality is the "what" of the service; functional quality is the "how."
Producer risk.
A brainstorming tool that shows the connections between ideas.

13. If a Cp shows that a process is not capable - should you calculate Cpk?
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
No -- if it is not the same - it can only be worse!
Lean is waste reduction - Six Sigma is variation reduction.
A random variable that summarizes the information from the sample(s).

14. Advantages of DOE
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
The gap between specifications and how service is performed.
1.Interactions can be detected and measured 2.Each value does the work of several values 3.Experimental error is quantified and used to determine the confidence the experimenter has in the conclusions
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

15. To what does the Six in Six Sigma relate?
Supplier - input - process - output - customer.
3.4 (assuming 1.5 sigma shift in the mean)
The target number of standard deviations from the mean for specifications.
A random variable that summarizes the information from the sample(s).

16. Risk Priority Number RPN
The target number of standard deviations from the mean for specifications.
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Represents the behavior of a process
The number of standard deviations some value is from the mean.

17. What is a spaghetti diagram?
Fitness for use.
The degree to which a product meets pre-established standards.
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.
A tool that shows the physical flows through a space.

18. In a regression - what does the standard error of the estimate tell you?
They move closer to the center line.
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.
What the value of the dependent variable is when the independent variable is zero.
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.

19. What is a run chart?
A tools that is used to measure the amount of variation in the measurement system arising from the measurement device (repeatability) and the people taking the measurement (reproducibility).
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
Fewer good units to sell - increased variable cost/unit.
A time series plot.

20. Affinity Diagrams
Define - measure - analyze - design - verify.
Organize ideas into meaningful categories by recognizing their underlying similarity
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Taguchi

21. In Juran's Cost of Quality model - which categories of costs balance which other categories?
To manage the Six Sigma project.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
Hold all input variables constant except one. Observe the response as you vary the single input.
Prevention and appraisal costs are balanced against internal and external failure.

22. Process occurance ranking
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
An assertion or conjecture concerning one or more populations
Hold all input variables constant except one. Observe the response as you vary the single input.
Waste.

23. In the Service Quality Gap Model - what is Gap 4?
The gap between what is promised and what is delivered.
Is the consequence of the failure.
Shows the temporal flow of activities in a project network.
Mean time to replacement.

24. What is the role of a master black belt?
To be a member of a Six Sigma project team.
Rapid improvement process.
99.73%
To mentor/coach (and sometimes train) black belts.

25. If your process is capable at two sigma - what percentage of the output will you have to inspect to find defectives?
100%
Speed - courtesy - competence - and ease of repair.
Consumer risk.
A scatterplot.

26. Define conformance quality.
Shifts - Trends - Repeating patterns - Correlation with known events
No -- the variation also has to be random and "expected."
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
The degree to which a product meets pre-established standards.

27. Residual(eij)
Used to create frequency distribution tally sheets
= yij - y(bar)i --> value minus sum of that treatment (of row)
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.
Brand image.

28. Failure Mode
Actual drawings - layouts - maps - etc which show where a defect occurs
Mean time to replacement.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
Is the way in which the failure is manifested.

29. Where should specifications fall in relation to ± 3 sigma for the process in order for a process to be capable.
Prevention and appraisal costs are balanced against internal and external failure.
Outside.
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.

30. What do you do when a process is out of control?
Is the way in which the failure is manifested.
Concluding there has not been an effect/change when there has.
Look for the assignable cause of non-random variation.
Defects Per Million Opportunities

31. What is CTQ?
The gap between specifications and how service is performed.
Critical to quality.
The manager in charge of a process being improved in a Six Sigma project.
To manage the Six Sigma project.

32. List two appraisal costs.
Pleasing to the senses.
Defects Per Million Opportunities
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
Fewer good units to sell - increased variable cost/unit.

33. What does SIPOC stand for?
The secondary characteristics of a product; "bells and whistles."
The number of standard deviations some value is from the mean.
Supplier - input - process - output - customer.
10 for Hazardous without warning 1 for none

34. How does Juran define quality?
The US national quality award.
Pleasing to the senses.
Fitness for use.
F_alpha - df(tr) - df (error)

35. Who is a process owner?
Technique used to relate through a model - one or more independent variables and a dependent variable (response)
p-bar - the long-run percent defective.
=sqrt((p*(1-p)/n)
The manager in charge of a process being improved in a Six Sigma project.

36. Pareto Analysis
Failure Modes and Effects Analysis
The process of ranking opportunities to determine which of many potential opportunities should be pursued first.
The number of standard deviations some value is from the mean.
A diagram that shows the relationships between activities in a project network.

37. What type of risk is associated with Type II Error?
Large enough to find two of the attribute - on average.
Sort - Set in Order - Shine - Standardize - Sustain
Consumer risk.
The manager in charge of a process being improved in a Six Sigma project.

38. What are the four categories of costs in Juran's framework?
Represents the behavior of a process
68%
Prevention - appraisal - internal failure - external failure.
Lower skill requirements - faster - less chance for error.

39. What is process capability?
Deming.
The number of standard deviations some value is from the mean.
The ability of a process to consistently meet customer specifications.
p-bar - the long-run percent defective.

40. In a regression - what does the coefficient of the intercept tell you
A scatterplot.
99.73%
What the value of the dependent variable is when the independent variable is zero.
No -- only if the process is also capable.

41. What is DPMO?
p-bar - the long-run percent defective.
Defects Per Million Opportunities
Prevention - appraisal - internal failure - external failure.
It's good -- but it's still out of control!

42. What is a Gage R&R?
A tools that is used to measure the amount of variation in the measurement system arising from the measurement device (repeatability) and the people taking the measurement (reproducibility).
Waste.
Another way to assess the significance of the analyzed factors is through a graphic procedure developed by C. Daniel when only one replicate (a single observation) was obtained:
A tool that shows performance along key dimensions all at once.

43. Why do you need two control charts for variables SPC?
Because the mean and standard deviation are independent of each other.
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
1.Interactions can be detected and measured 2.Each value does the work of several values 3.Experimental error is quantified and used to determine the confidence the experimenter has in the conclusions
Supplier - input - process - output - customer.

44. Regression
Represents the behavior of a process
To mentor/coach (and sometimes train) black belts.
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
The gap between what management thinks customers want and the process specifications.

45. DOE
Someone who is consistently against virtually everything.
10 for Hazardous without warning 1 for none
Controlling quality at the source.
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan

46. If a three-stage process has 90% yields at each stage - what is the overall yield?
No -- the variation also has to be random and "expected."
10 for Hazardous without warning 1 for none
Producer risk.
0.9^3 or 72.9%

47. When is Cpk used?
1.Interactions can be detected and measured 2.Each value does the work of several values 3.Experimental error is quantified and used to determine the confidence the experimenter has in the conclusions
The ratio of outputs to inputs; 1-scrap.
Large enough to find two of the attribute - on average.
To do a capability study for a non-centered process.

48. F value
F_alpha - df(tr) - df (error)
Another way to assess the significance of the analyzed factors is through a graphic procedure developed by C. Daniel when only one replicate (a single observation) was obtained:
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
Blame.

49. In your major - courses are pass-fail. Would you monitor performance using attribute or variable SPC?
The number of standard deviations some value is from the mean.
Attribute
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
Linearity - normality - homoscedasticity - independence.

50. If your process is capable at two sigma - what percentage of the output will be defective (assuming the process is in control)?
Concluding there has been an effect/change when there has not.
95%
Pleasing to the senses.
5%