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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. Define performance quality.
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
The primary operating characteristics of a product.
5%
Look for the assignable cause of non-random variation.

2. What is a dashboard?
A tool that shows performance along key dimensions all at once.
Initiated before or at design concept finalization
Before production starts
Fewer good units to sell - increased variable cost/unit.

3. What is Type 1 Error?
Attribute
Waste.
The primary operating characteristics of a product.
Concluding there has been an effect/change when there has not.

4. What is Little's Law?
Inventory = throughput x flow time.
=sqrt((p*(1-p)/n)
Central Limit Theorem
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

5. Uses of regression
0.9^3 or 72.9%
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
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.

6. Manual Test for Nomality
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
Outside.

7. Define durability.
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
To do a capability study for a non-centered process.
Mean time to replacement.
Producer risk.

8. Cause and Effect Diagrams
Concluding there has not been an effect/change when there has.
Method developed by Ishikawa to graphically display the causes of any given problem
A descending order-sorted bar chart with a cumulative percentage line.
Deming.

9. What is the formula for standard deviation?
Critical to quality.
=sqrt(Σ(x-x-bar)^2)/(n-1))
Because the mean and standard deviation are independent of each other.
Actual drawings - layouts - maps - etc which show where a defect occurs

10. In the Service Quality Gap Model - what is Gap 5?
The gap between what customers expect and the service they receive.
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.
Actual drawings - layouts - maps - etc which show where a defect occurs
Variable.

11. Failure cause
Is what induces the failure
Not necessarily.
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
Consumer risk.

12. What is a spaghetti diagram?
Attribute.
Critical to quality.
A tool that shows the physical flows through a space.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables

13. What does a project prioritization matrix do?
Represents the behavior of a process
95%
Sort - Set in Order - Shine - Standardize - Sustain
Assigns scores to weighted criteria for each project under consideration.

14. F value
F_alpha - df(tr) - df (error)
Attribute
The ratio of outputs to inputs; 1-scrap.
QFD

15. To what does the Six in Six Sigma relate?
To monitor a process when measurement by attribute is used.
Producer risk.
= yij - y(bar)i --> value minus sum of that treatment (of row)
The target number of standard deviations from the mean for specifications.

16. What are the four regression assumptions?
Sort - Set in Order - Shine - Standardize - Sustain
Linearity - normality - homoscedasticity - independence.
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
Lower control limit.

17. Approximately what percent of a normal distribution falls between ± 2 standard deviations from the mean?
Is what induces the failure
Through producer/consumer negotiation.
Sort - Set in Order - Shine - Standardize - Sustain
95%

18. Effect ranking (Severity of the Defect)
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
To monitor a process when measurement by variables is used.
Shifts - Trends - Repeating patterns - Correlation with known events
10 for Hazardous without warning 1 for none

19. What is an affinity diagram?
The process of ranking opportunities to determine which of many potential opportunities should be pursued first.
Fishbone - cause-and-effect diagram.
A brainstorming tool that shows the connections between ideas.
Represents the behavior of a process

20. Non-random patterns (Run Charts)
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.
Financial - customer - internal process - innovation and learning.
Shifts - Trends - Repeating patterns - Correlation with known events
It looks to minimize the probability of a failure - or to minimize its effects

21. What size should samples be for attribute SPC?
The gap between what customers expect and the service they receive.
Large enough to find two of the attribute - on average.
Before production starts
The manager in charge of a process being improved in a Six Sigma project.

22. Defect check sheets
Different types of defects are listed (used for Pareto chart)
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
Sort - Set in Order - Shine - Standardize - Sustain

23. Define takt time.
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.
Mistake-proofing.
Technique used to relate through a model - one or more independent variables and a dependent variable (response)

24. PFMEA
Hold all input variables constant except one. Observe the response as you vary the single input.
A random variable that summarizes the information from the sample(s).
Before production starts
Large enough to find two of the attribute - on average.

25. DOE
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
To mentor/coach (and sometimes train) black belts.

26. What is a run chart?
Mean time to failure.
The gap between what management thinks customers want and what customers really want.
A time series plot.
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

27. If you can only collect categorical data - what type of SPC charting can you do?
Concluding there has been an effect/change when there has not.
Attribute.
Attribute
They move closer to the center line.

28. In a Z table - what is Z?
The number of standard deviations some value is from the mean.
Look for the assignable cause of non-random variation.
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
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces

29. What is a network diagram?
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
A diagram that shows the relationships between activities in a project network.
Define - measure - analyze - design - verify.
The gap between what management thinks customers want and the process specifications.

30. Uses of regression - Control
Observed variation in response is caused by the input
F_alpha - df(tr) - df (error)
Variable.
To obtain a certain desirable outcome from the process

31. What type of risk is associated with Type II Error?
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
Consumer risk.
The target number of standard deviations from the mean for specifications.
Defects Per Million Opportunities

32. What is the center line of a p-chart?
p-bar - the long-run percent defective.
Prevention and appraisal costs are balanced against internal and external failure.
Observed variation in response is caused by the input
To monitor a process when measurement by variables is used.

33. What is Kaizen?
No -- only if the process is also capable.
5%
Rapid improvement process.
Attribute

34. Test for Independence
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
The gap between what management thinks customers want and the process specifications.
Sort - Set in Order - Shine - Standardize - Sustain
Upper control limit.

35. Does it ever make sense to accept a job when a process is incapable?
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
The House of Quality.
Supplier - input - process - output - customer.
Pleasing to the senses.

36. What are the Five Dimensions of Service Quality?
=sqrt((p*(1-p)/n)
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.
Reliability - Assurance - Responsiveness - Tangibles - Empathy

37. What does DMAIC stand for?
Method developed by Ishikawa to graphically display the causes of any given problem
Define - measure - analyze - improve - control.
Is the consequence of the failure.
Used to create frequency distribution tally sheets

38. 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).
Sampling for SPC is done real time.
The target number of standard deviations from the mean for specifications.
Rapid improvement process.

39. In your major - courses are pass-fail. Would you monitor performance using attribute or variable SPC?
Attribute
10 if Almost impossible to detect
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
Supplier - input - process - output - customer.

40. Residual
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
Failure Modes and Effects Analysis
An assertion or conjecture concerning one or more populations
It looks to minimize the probability of a failure - or to minimize its effects

41. Your production process meets customer specifications. Is your process in control?
X-bar-bar
Not necessarily.
3.4 (assuming 1.5 sigma shift in the mean)
Observed variation in response is caused by the input

42. What is the role of a green belt?
Central Limit Theorem
To be a member of a Six Sigma project team.
5%
=sqrt(Σ(x-x-bar)^2)/(n-1))

43. Test for constant variance
F_alpha - df(tr) - df (error)
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.
Critical to quality.
No -- if it is not the same - it can only be worse!

44. What are the four categories of costs in Juran's framework?
Prevention - appraisal - internal failure - external failure.
Upper control limit.
It's good -- but it's still out of control!
Prediction and estimation. based on an unknown x value - estimation is based on a known x value

45. What is a Gage R&R?
To be a member of a Six Sigma project team.
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).
The US national quality award.
A tool that shows where there is waste in a process.

46. List two components of external failure.
Someone who is consistently against virtually everything.
Complaint adjustment - returned material - warranty charges - allowances - loss of future business.
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:
Is the consequence of the failure.

47. What is the role of a master black belt?
To do a capability study for a non-centered process.
Causes that lead to a particular effect.
Central Limit Theorem
To mentor/coach (and sometimes train) black belts.

48. In Juran's Cost of Quality model - which categories of costs balance which other categories?
Prevention and appraisal costs are balanced against internal and external failure.
No -- the variation also has to be random and "expected."
The cycle time required to meet demand.
Fishbone - cause-and-effect diagram.

49. TWO-DIMENTIONAL SCATTER PLOT
Represents the behavior of a process
Lower skill requirements - faster - less chance for error.
Through producer/consumer negotiation.
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables

50. What do you do when a process is out of control?
Brand image.
Look for the assignable cause of non-random variation.
The gap between what management thinks customers want and the process specifications.
The Japanese national quality award.