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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 are two other names for an Ishikawa diagram?
Fishbone - cause-and-effect diagram.
Defects Per Million Opportunities
Fewer good units to sell - increased variable cost/unit.
It looks to minimize the probability of a failure - or to minimize its effects

2. Definition of Interaction
99.73%
Lower control limit.
Speed - courtesy - competence - and ease of repair.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables

3. Detection Criteria Ranking
Upper control limit.
100%
A random variable that summarizes the information from the sample(s).
10 if Almost impossible to detect

4. Failure cause
The House of Quality.
To obtain a certain desirable outcome from the process
Prevention - appraisal - internal failure - external failure.
Is what induces the failure

5. What happens to control limits on an SPC chart when sample size is increased?
They move closer to the center line.
A tool that shows performance along key dimensions all at once.
Consumer risk.
An assertion or conjecture concerning one or more populations

6. If a three-stage process has 90% yields at each stage - what is the overall yield?
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
0.9^3 or 72.9%
Prevention - appraisal - internal failure - external failure.
Failure Modes and Effects Analysis

7. What is a dashboard?
Yes - when there are opportunities to improve - when contribution margin is adequate - when achieving market share is important.
68%
A tool that shows performance along key dimensions all at once.
Define - measure - analyze - improve - control.

8. With Six Sigma capability - how many defects per million opportunities would you see?
Workers - machines - materials.
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
A tool that shows performance along key dimensions all at once.
3.4 (assuming 1.5 sigma shift in the mean)

9. Which quality guru developed the concept of loss to society?
Look for the assignable cause of non-random variation.
Taguchi
Concluding there has been an effect/change when there has not.
Failure Modes and Effects Analysis

10. In a regression - what does R-square tell you?
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
Look for the assignable cause of non-random variation.
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions

11. 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
Because the mean and standard deviation are independent of each other.
Lean is waste reduction - Six Sigma is variation reduction.
If the Response vs. Levels graph if the response lines are not parallel (crossing)

12. Failure effect
The gap between what customers expect and the service they receive.
Is the consequence of the failure.
Someone who is consistently against virtually everything.
Represent the errors which are random variables with an assumed normal distribution with mean zero and a constant variance σ2.

13. What is Type II Error?
A time series plot.
Concluding there has not been an effect/change when there has.
Financial - customer - internal process - innovation and learning.
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).

14. What are the four perspectives of the Balanced Scorecard?
To monitor a process when measurement by attribute is used.
X-bar-bar
A tool that shows the physical flows through a space.
Financial - customer - internal process - innovation and learning.

15. In a regression - what does the standard error of the estimate tell you?
Consumer risk.
Lean is waste reduction - Six Sigma is variation reduction.
No -- the variation also has to be random and "expected."
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.

16. What inventory approach contributes to process quality by "lowering the river to find the rocks?"
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.
Lean (or JIT).
Pleasing to the senses.
The gap between what is promised and what is delivered.

17. What is Jidoka?
No -- if it is not the same - it can only be worse!
Taguchi
To monitor a process when measurement by attribute is used.
Controlling quality at the source.

18. What is Type 1 Error?
Concluding there has been an effect/change when there has not.
What the value of the dependent variable is when the independent variable is zero.
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan
Different types of defects are listed (used for Pareto chart)

19. What is process capability?
Actual drawings - layouts - maps - etc which show where a defect occurs
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Can't tell without a Range chart.
The ability of a process to consistently meet customer specifications.

20. Cause and Effect Diagrams
Method developed by Ishikawa to graphically display the causes of any given problem
Concluding there has not been an effect/change when there has.
The target number of standard deviations from the mean for specifications.
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

21. What is the difference between Lean and Six Sigma?
Failure Modes and Effects Analysis
Lean is waste reduction - Six Sigma is variation reduction.
68%
Look for the assignable cause of non-random variation.

22. For your SPC sample you weigh bags of potatoes. Is this variable or attribute SPC?
Variable.
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.
Upper control limit.
68%

23. What percentage of a normal distribution lies above the mean?
A tool that shows where there is waste in a process.
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
50%
The gap between what is promised and what is delivered.

24. In a regression - what does the p value of F tell you?
Is what induces the failure
The secondary characteristics of a product; "bells and whistles."
Shows the temporal flow of activities in a project network.
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).

25. Taguchi's experimental designs are of this type.
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).
Sort - Set in Order - Shine - Standardize - Sustain
Fractional factorial designs (orthogonal arrays)
Represents the behavior of a process

26. What type of risk is associated with Type II Error?
Sort - Set in Order - Shine - Standardize - Sustain
10 for Hazardous without warning 1 for none
Inventory = throughput x flow time.
Consumer risk.

27. What is a network diagram?
Variable.
A diagram that shows the relationships between activities in a project network.
Lean (or JIT).
The number of standard deviations some value is from the mean.

28. What is a run chart?
Supplier - input - process - output - customer.
Taguchi
F_alpha - df(tr) - df (error)
A time series plot.

29. You have been plotting sample means on an x-bar chart and all points indicate normal - expected variation. Is the process in control?

30. What is DMADV?
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
Can't tell without a Range chart.
The secondary characteristics of a product; "bells and whistles."
Define - measure - analyze - design - verify.

31. If you can only collect categorical data - what type of SPC charting can you do?
To monitor a process when measurement by attribute is used.
Attribute.
A tool that shows where there is waste in a process.
To be a member of a Six Sigma project team.

32. List two components of prevention cost.
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.
A random variable that summarizes the information from the sample(s).
Define - measure - analyze - improve - control.
A scatterplot.

33. Pareto Analysis
The process of ranking opportunities to determine which of many potential opportunities should be pursued first.
10 for Hazardous without warning 1 for none
Blame.
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions

34. What is FMEA?
False - because each machine will have different natural tolerances.
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
Financial - customer - internal process - innovation and learning.
Failure Modes and Effects Analysis

35. What is the formula for standard deviation?
The gap between what customers expect and the service they receive.
The number of standard deviations some value is from the mean.
=sqrt(Σ(x-x-bar)^2)/(n-1))
Fishbone - cause-and-effect diagram.

36. Define product reliability.
If the Response vs. Levels graph if the response lines are not parallel (crossing)
Mean time to failure.
Sampling for SPC is done real time.
The amount of variation in the dependent variable that is explained by the variation in the independent variable(s).

37. When yields decrease - what are the two effects on contribution?
p-bar - the long-run percent defective.
To manage the Six Sigma project.
Fewer good units to sell - increased variable cost/unit.
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).

38. 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.
An assertion or conjecture concerning one or more populations
5%
Scrap - rework - retest - downtime - yield losses - disposition costs.

39. If you have calculated a Cpk - should you also calculate a Cp?
Supplier - input - process - output - customer.
A brainstorming tool that shows the connections between ideas.
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
To be a member of a Six Sigma project team.

40. What is a spaghetti diagram?
A tool that shows the physical flows through a space.
What the value of the dependent variable is when the independent variable is zero.
= 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
Lean (or JIT).

41. Regression
Represents the behavior of a process
Define - measure - analyze - design - verify.
Hold all input variables constant except one. Observe the response as you vary the single input.
Lower skill requirements - faster - less chance for error.

42. Defect check sheets
Different types of defects are listed (used for Pareto 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).
A random variable that summarizes the information from the sample(s).
It looks to minimize the probability of a failure - or to minimize its effects

43. In a regression - what does the coefficient of the intercept tell you
Shows the temporal flow of activities in a project network.
No -- only if the process is also capable.
What the value of the dependent variable is when the independent variable is zero.
A tool that shows performance along key dimensions all at once.

44. If your process is capable at two sigma - what percentage of the output will you have to inspect to find defectives?
To be a member of a Six Sigma project team.
100%
The gap between what management thinks customers want and the process specifications.
To monitor a process when measurement by variables is used.

45. In the Service Quality Gap Model - what is Gap 4?
The gap between what is promised and what is delivered.
QFD
Speed - courtesy - competence - and ease of repair.
Producer risk.

46. Define takt time.
10 for Hazardous without warning 1 for none
Variable.
= yij - y(bar)i --> value minus sum of that treatment (of row)
The cycle time required to meet demand.

47. How does Juran define quality?
Fitness for use.
An assertion or conjecture concerning one or more populations
Lean (or JIT).
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.

48. Affinity Diagrams
Lower control limit.
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
No -- if it is not the same - it can only be worse!
The target number of standard deviations from the mean for specifications.

49. What is the role of a green belt?
The gap between what management thinks customers want and what customers really want.
The House of Quality.
To be a member of a Six Sigma project team.
What the value of the dependent variable is when the independent variable is zero.

50. Test for constant variance
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.
Mean time to failure.
Before production starts
50%