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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 Little's Law?
They move closer to the center line.
To obtain a certain desirable outcome from the process
Taguchi
Inventory = throughput x flow time.

2. When yields decrease - what are the two effects on contribution?
Producer risk.
Fewer good units to sell - increased variable cost/unit.
Sort - Set in Order - Shine - Standardize - Sustain
System to reduce waste and optimize productivity through maintaining an orderly workplace and using visual cues to achieve more consistent operational results.

3. DOE
A tool that shows where there is waste in a process.
p-bar - the long-run percent defective.
The gap between what is promised and what is delivered.
An experiment where one or more variables believed to have an effect on an experimental outcome are identified and manipulated according to a plan

4. If you have calculated a Cpk - should you also calculate a Cp?
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
An interaction is defined as a dependence relationship between the response and the levels of two or more variables
95%
To monitor a process when measurement by attribute is used.

5. 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?
No -- only if the process is also capable.
False - because each machine will have different natural tolerances.
Prevention - appraisal - internal failure - external failure.
Linearity - normality - homoscedasticity - independence.

6. If your process is capable at two sigma - what percentage of the output will you have to inspect to find defectives?
Concluding there has not been an effect/change when there has.
= yij - y(bar)i --> value minus sum of that treatment (of row)
100%
The cycle time required to meet demand.

7. Where should specifications fall in relation to ± 3 sigma for the process in order for a process to be capable.
To monitor a process when measurement by attribute is used.
Outside.
A tool that shows where there is waste in a process.
Someone who is consistently against virtually everything.

8. One factor at a time (OFAT)
Attribute
Hold all input variables constant except one. Observe the response as you vary the single input.
Look for the assignable cause of non-random variation.
Prevention - appraisal - internal failure - external failure.

9. Failure Mode
Lower 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
Is the way in which the failure is manifested.
Shifts - Trends - Repeating patterns - Correlation with known events

10. What is written on the "spines" of a fishbone diagram?
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
Failure Modes and Effects Analysis
Causes that lead to a particular effect.
Critical to quality.

11. What is process capability?
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
Concluding there has not been an effect/change when there has.
The ability of a process to consistently meet customer specifications.
Used to create frequency distribution tally sheets

12. FMEA
Speed - courtesy - competence - and ease of repair.
Variable.
Supplier - input - process - output - customer.
It looks to minimize the probability of a failure - or to minimize its effects

13. What is muda
Upper control limit.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
Waste.
Sampling for SPC is done real time.

14. Approximately what percent of a normal distribution falls between ± 2 standard deviations from the mean?
Define - measure - analyze - design - verify.
95%
Because the mean and standard deviation are independent of each other.
99.73%

15. What is a CAVE man?
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
How much variance you expect around the prediction; two SEs gives you a 95% confidence interval.
50%
Someone who is consistently against virtually everything.

16. When either attribute or variable measures could be used for SPC - why might attribute measurement be preferred?
A time series plot.
Lower skill requirements - faster - less chance for error.
Through producer/consumer negotiation.
Scrap - rework - retest - downtime - yield losses - disposition costs.

17. In the Service Quality Gap Model - what is Gap 2?
Because the mean and standard deviation are independent of each other.
The gap between what management thinks customers want and the process specifications.
68%
A random variable that summarizes the information from the sample(s).

18. List Garvin's eight dimensions of product quality.
Performance - features - conformance - reliability - durability - serviceability - aesthetics - perceived quality
The ability of a process to consistently meet customer specifications.
Reliability - Assurance - Responsiveness - Tangibles - Empathy
Represents the behavior of a process

19. List two components of prevention cost.
Someone who is consistently against virtually everything.
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.
Look for the assignable cause of non-random variation.
Shows the temporal flow of activities in a project network.

20. What are the Five Dimensions of Service Quality?
A brainstorming tool that shows the connections between ideas.
Is the way in which the failure is manifested.
Reliability - Assurance - Responsiveness - Tangibles - Empathy
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median

21. What is a Gantt chart?
Organize ideas into meaningful categories by recognizing their underlying similarity
100%
The gap between what customers expect and the service they receive.
Shows the temporal flow of activities in a project network.

22. Define conformance quality.
Lean is waste reduction - Six Sigma is variation reduction.
The degree to which a product meets pre-established standards.
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions
Pleasing to the senses.

23. What quality tool formally incorporates the voice of the customer?
Reliability - Assurance - Responsiveness - Tangibles - Empathy
Define - measure - analyze - improve - control.
The gap between what customers expect and the service they receive.
QFD

24. The Test Statistic (TS)
The House of Quality.
To monitor a process when measurement by attribute is used.
The cycle time required to meet demand.
A random variable that summarizes the information from the sample(s).

25. What graphical tool is used to show the relationship between two numerical variables?
99.73%
A scatterplot.
Kaoru Ishikawa.
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

26. What is a histogram?
Shifts - Trends - Repeating patterns - Correlation with known events
A chart that breaks the range of data into equal intervals and then shows the count of occurrences in each interval.
The gap between what management thinks customers want and the process specifications.
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.

27. What is the center line of a p-chart?
They move closer to the center line.
Attribute.
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
p-bar - the long-run percent defective.

28. What is the formula for standard deviation?
=sqrt(Σ(x-x-bar)^2)/(n-1))
An assertion or conjecture concerning one or more populations
Technique used to relate through a model - one or more independent variables and a dependent variable (response)
Is what induces the failure

29. Define takt time.
What the value of the dependent variable is when the independent variable is zero.
The cycle time required to meet demand.
Mean time to failure.
Conformance to specifications.

30. Define product reliability.
Before production starts
The gap between what customers expect and the service they receive.
What the value of the dependent variable is when the independent variable is zero.
Mean time to failure.

31. What are the four categories of costs in Juran's framework?
Prevention - appraisal - internal failure - external failure.
Prediction and estimation. based on an unknown x value - estimation is based on a known x value
=sqrt((p*(1-p)/n)
Inventory = throughput x flow time.

32. In a Z table - what is Z?
The number of standard deviations some value is from the mean.
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:
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
Is the consequence of the failure.

33. Simple Regression Analysis (one factor regression model)
Mistake-proofing.
Scrap - rework - retest - downtime - yield losses - disposition costs.
= 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
To mentor/coach (and sometimes train) black belts.

34. Process occurance ranking
Look to your customer - not to other firms. "You can always find someone shorter - fatter and balder!"
Rank of 10 if there is >= 100 per 1000 piece Rank of 1 if there is <=.01 per 1000 pieces
The secondary characteristics of a product; "bells and whistles."
Central Limit Theorem

35. Approximately what percent of a normal distribution falls between ± 3 standard deviations from the mean?
99.73%
Initiated before or at design concept finalization
False - because each machine will have different natural tolerances.
Quality planning - design review - education and training - process control - IS costs - quality reporting - improvement project costs - working with suppliers before production.

36. Creating a Run Chart
1) Plot a Line chart of the data in time sequence 2) Draw a line at the median
10 if Almost impossible to detect
Blame.
Upper control limit.

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

38. Cause and Effect Diagrams
Vary two or more variables simultaneously - Multiple measurements are obtained under the same experimental conditions
No; if the process is centered - Cp will be the same; if not - Cpk is what you need to determine capabilty.
Incoming materials inspection - inspection and testing - maintaining test equipment - materials/services consumed
Method developed by Ishikawa to graphically display the causes of any given problem

39. What inventory approach contributes to process quality by "lowering the river to find the rocks?"
A diagram that shows the relationships between activities in a project network.
0.9^3 or 72.9%
The primary operating characteristics of a product.
Lean (or JIT).

40. Define perceived quality (Garvin's framework).
Walter A. Shewhart
Brand image.
Mean time to failure.
A tool that shows where there is waste in a process.

41. Defect location check sheets
To manage the Six Sigma project.
Concluding there has not been an effect/change when there has.
Before production starts
Actual drawings - layouts - maps - etc which show where a defect occurs

42. In the Service Quality Gap Model - what is Gap 1?
Different types of defects are listed (used for Pareto chart)
=sqrt(Σ(x-x-bar)^2)/(n-1))
The gap between what management thinks customers want and what customers really want.
Data reduction to put a large number of qualitative inputs into a smaller number of major dimensions

43. Failure effect
95%
To monitor a process when measurement by attribute is used.
50%
Is the consequence of the failure.

44. If your process is capable at two sigma - what percentage of the output will be defective (assuming the process is in control)?
No -- if it is not the same - it can only be worse!
Mistake-proofing.
5%
Lean is waste reduction - Six Sigma is variation reduction.

45. What is the role of a master black belt?
To mentor/coach (and sometimes train) black belts.
Failure Modes and Effects Analysis
The target number of standard deviations from the mean for specifications.
Controlling quality at the source.

46. PFMEA
Before production starts
Producer risk.
The manager in charge of a process being improved in a Six Sigma project.
Shows the temporal flow of activities in a project network.

47. With Six Sigma capability - how many defects per million opportunities would you see?
They move closer to the center line.
3.4 (assuming 1.5 sigma shift in the mean)
The US national quality award.
Organize ideas into meaningful categories by recognizing their underlying similarity

48. Manual Test for Nomality
Consumer risk.
Not necessarily.
1) Obtain Residuals 2) Fill out table --> y coordinates: F = 100 (i-.5)/N x coordinates: Ordered Residual 3) Plot on Normal Probability Paper
Upper control limit.

49. Complete this quality phrase: 'Fix the process - not the _____.'
A tool that shows where there is waste in a process.
Blame.
Linearity - normality - homoscedasticity - independence.
Method developed by Ishikawa to graphically display the causes of any given problem

50. Your production process meets customer specifications. Is your process in control?
= S x O x D S--> Severity O--> Occurrence D--> Detection Higher the number the worse it is
Define - measure - analyze - improve - control.
Walter A. Shewhart
Not necessarily.