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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. Failure effect
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
Is the consequence of the failure.
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.
5%

2. Why do you need two control charts for variables SPC?
Because the mean and standard deviation are independent of each other.
The target number of standard deviations from the mean for specifications.
A diagram that shows the relationships between activities in a project network.
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.

3. Based on what principal can we use the normal distribution assumptions for SPC?
The manager in charge of a process being improved in a Six Sigma project.
X-bar-bar
Someone who is consistently against virtually everything.
Central Limit Theorem

4. In a regression - what does the coefficient of the intercept tell you
Shifts - Trends - Repeating patterns - Correlation with known events
Technique used to relate through a model - one or more independent variables and a dependent variable (response)
What the value of the dependent variable is when the independent variable is zero.
Attribute.

5. What does SIPOC stand for?
Kaoru Ishikawa.
The gap between what management thinks customers want and what customers really want.
3.4 (assuming 1.5 sigma shift in the mean)
Supplier - input - process - output - customer.

6. Define conformance quality.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
Walter A. Shewhart
The degree to which a product meets pre-established standards.
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

7. One factor at a time (OFAT)
Observed variation in response is caused by the input
Rapid improvement process.
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
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

8. In the Service Quality Gap Model - what is Gap 4?
A time series plot.
Variable.
Sampling for SPC is done real time.
The gap between what is promised and what is delivered.

9. What is Value Stream Mapping?
Upper control limit.
Method developed by Ishikawa to graphically display the causes of any given problem
The number of standard deviations some value is from the mean.
A tool that shows where there is waste in a process.

10. Statistical Hypothesis
An assertion or conjecture concerning one or more populations
It looks to minimize the probability of a failure - or to minimize its effects
No -- if it is not the same - it can only be worse!
= yij - y(bar)i --> value minus sum of that treatment (of row)

11. What size should samples be for attribute SPC?
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
Large enough to find two of the attribute - on average.
Actual drawings - layouts - maps - etc which show where a defect occurs
Waste.

12. What are the four categories of costs in Juran's framework?
Mistake-proofing.
Variable.
Attribute
Prevention - appraisal - internal failure - external failure.

13. What is the difference between the way sampling is done for SPC and for acceptance sampling?
Sampling for SPC is done real time.
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
Kaoru Ishikawa.
68%

14. Stratified defect check sheets
Central Limit Theorem
Concluding there has not been an effect/change when there has.
100%
Stratify a particular defect type according to logical criteria

15. For what is a p-chart used?
Attribute
To monitor a process when measurement by attribute is used.
A tool that shows the physical flows through a space.
Prevention and appraisal costs are balanced against internal and external failure.

16. TWO-DIMENTIONAL SCATTER PLOT
10 if Almost impossible to detect
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables
An interaction is defined as a dependence relationship between the response and the levels of two or more variables

17. Definition of Interaction
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
Lower skill requirements - faster - less chance for error.
The US national quality award.
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables

18. If you can only collect categorical data - what type of SPC charting can you do?
Sampling for SPC is done real time.
An assertion or conjecture concerning one or more populations
Attribute.
95%

19. Define aesthetic quality.
Pleasing to the senses.
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
The gap between what management thinks customers want and the process specifications.
The manager in charge of a process being improved in a Six Sigma project.

20. How does Juran define quality?
Used to create frequency distribution tally sheets
Fitness for use.
No -- only if the process is also capable.
An assertion or conjecture concerning one or more populations

21. Creating a Run Chart
Speed - courtesy - competence - and ease of repair.
A simple graph between two variables - visualize the type - degree of strength and shape of the relationship between two variables
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
Variable.

22. If your process is capable at two sigma - what percentage of the output will you have to inspect to find defectives?
100%
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
= 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
Causes that lead to a particular effect.

23. What is a histogram?
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
Define - measure - analyze - design - verify.
Is the way in which the failure is manifested.
Scrap - rework - retest - downtime - yield losses - disposition costs.

24. If you have calculated a Cpk - should you also calculate a Cp?
The US national quality award.
Upper control limit.
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
Mean time to failure.

25. Who is a process owner?
No -- the variation also has to be random and "expected."
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.
The manager in charge of a process being improved in a Six Sigma project.
Look for the assignable cause of non-random variation.

26. What is Little's Law?
Inventory = throughput x flow time.
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
An interaction is defined as a dependence relationship between the response and the levels of two or more variables

27. Effect ranking (Severity of the Defect)
Stratify a particular defect type according to logical criteria
10 for Hazardous without warning 1 for none
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
The Japanese national quality award.

28. Manual Test for Nomality
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
95%
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

29. What is the center line of an X-bar chart?
Initiated before or at design concept finalization
The cycle time required to meet demand.
X-bar-bar
Sort - Set in Order - Shine - Standardize - Sustain

30. There are two milling machines in the shop. Data has been collected on one to compute control limits for both. This is acceptable SPC practice - true or false and why?
Controlling quality at the source.
False - because each machine will have different natural tolerances.
Mistake-proofing.
= yij - y(bar)i --> value minus sum of that treatment (of row)

31. Who first studied randomness in industrial processes
=sqrt(Σ(x-x-bar)^2)/(n-1))
Walter A. Shewhart
Brand image.
Mean time to replacement.

32. What is a CAVE man?
Upper control limit.
Someone who is consistently against virtually everything.
68%
It's good -- but it's still out of control!

33. Failure cause
Is what induces the failure
It looks to minimize the probability of a failure - or to minimize its effects
Walter A. Shewhart
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed

34. Failure Mode
Through producer/consumer negotiation.
Speed - courtesy - competence - and ease of repair.
To do a capability study for a non-centered process.
Is the way in which the failure is manifested.

35. Define product reliability.
No -- only if the process is also capable.
A brainstorming tool that shows the connections between ideas.
Mean time to failure.
Technical quality is the "what" of the service; functional quality is the "how."

36. In your major - courses are pass-fail. Would you monitor performance using attribute or variable SPC?
Waste.
Attribute
Producer risk.
Can't tell without a Range chart.

37. If a three-stage process has 90% yields at each stage - what is the overall yield?
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
= yij - y(bar)i --> value minus sum of that treatment (of row)
The Japanese national quality award.
0.9^3 or 72.9%

38. What is a network diagram?
A tool that shows where there is waste in a process.
The degree to which a product meets pre-established standards.
Fishbone - cause-and-effect diagram.
A diagram that shows the relationships between activities in a project network.

39. What is the 5S model?
No -- the variation also has to be random and "expected."
Taguchi
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.
Supplier - input - process - output - customer.

40. To what does the Six in Six Sigma relate?
Technical quality is the "what" of the service; functional quality is the "how."
= yij - y(bar)i --> value minus sum of that treatment (of row)
A scatterplot.
The target number of standard deviations from the mean for specifications.

41. Process occurance ranking
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
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).
Mean time to failure.
10 for Hazardous without warning 1 for none

42. 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).
3.4 (assuming 1.5 sigma shift in the mean)
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
Used to create frequency distribution tally sheets

43. In Juran's Cost of Quality model - which categories of costs balance which other categories?
Prevention - appraisal - internal failure - external failure.
Defects Per Million Opportunities
Prevention and appraisal costs are balanced against internal and external failure.
No -- only if the process is also capable.

44. What quality tool formally incorporates the voice of the customer?
100%
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Blame.
QFD

45. What is CTQ?
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.
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
Failure Modes and Effects Analysis
Critical to quality.

46. In the Service Quality Gap Model - what is Gap 5?
The gap between what customers expect and the service they receive.
Studying firms with the best performance in a particular area.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
A diagram that shows the relationships between activities in a project network.

47. List Garvin's eight dimensions of product quality.
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
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).
QFD
Is what induces the failure

48. Does it ever make sense to accept a job when a process is incapable?
Critical to quality.
Consumer risk.
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces

49. What is process capability?
The gap between what customers expect and the service they receive.
Central Limit Theorem
To monitor a process when measurement by attribute is used.
The ability of a process to consistently meet customer specifications.

50. Explain the difference between technical and functional service quality.
Technical quality is the "what" of the service; functional quality is the "how."
To be a member of a Six Sigma project team.
A descending order-sorted bar chart with a cumulative percentage line.
A tool that shows where there is waste in a process.