Lean Six Sigma Green Belt Certification Prep 4 — Questions and Answers
Question 1: What is a 'Kaizen event' in Lean Six Sigma?
- A long-term project lasting 6-12 months
- A focused, rapid improvement workshop typically lasting 3-5 days (Correct answer)
- A customer feedback session
- A quarterly management review
Correct answer: A focused, rapid improvement workshop typically lasting 3-5 days
A Kaizen event (also called a Kaizen blitz or rapid improvement event) is an intensive short-duration workshop where a cross-functional team implements improvements quickly.
Question 2: When a control chart shows a run of 8 consecutive points on one side of the centerline, this is called:
- Random variation
- A special cause signal (Correct answer)
- Common cause variation
- A natural pattern
Correct answer: A special cause signal
Eight consecutive points on one side of the centerline is a classic Western Electric rule violation indicating a process shift — a special cause that requires investigation.
Question 3: What is the difference between 'precision' and 'accuracy' in measurement systems?
- Precision is hitting the target; accuracy is consistency
- Accuracy is closeness to the true value; precision is consistency of repeated measurements (Correct answer)
- They are synonyms in Six Sigma
- Precision applies to variables data; accuracy to attribute data
Correct answer: Accuracy is closeness to the true value; precision is consistency of repeated measurements
Accuracy (bias) refers to how close measurements are to the true value, while precision (repeatability) refers to how consistent repeated measurements are.
Question 4: A process yield is 95%. What is the First Pass Yield (FPY) for a three-step process where each step has 95% yield?
- 95%
- 85%
- 85.7% (Correct answer)
- 90%
Correct answer: 85.7%
FPY for multiple steps is calculated by multiplying individual step yields: 0.95 × 0.95 × 0.95 = 0.857 or approximately 85.7%.
Question 5: Which of the following is NOT one of the five principles of Lean thinking?
- Identify value
- Map the value stream
- Eliminate defects to zero (Correct answer)
- Pursue perfection
Correct answer: Eliminate defects to zero
The five Lean principles are: Identify Value, Map the Value Stream, Create Flow, Establish Pull, and Pursue Perfection — 'eliminate defects to zero' is not one of them.
Question 6: In regression analysis, what does an R² value of 0.85 indicate?
- The correlation coefficient is 0.85
- 85% of the variation in Y is explained by the X variable(s) (Correct answer)
- The model has 85% accuracy
- 15% of data points are outliers
Correct answer: 85% of the variation in Y is explained by the X variable(s)
R² (coefficient of determination) represents the proportion of variation in the response variable explained by the model — 0.85 means 85% is explained.
Question 7: What is the role of the 'Champion' in a Six Sigma organizational structure?
- Leads the day-to-day project work and statistical analysis
- A senior leader who sponsors and removes barriers for Six Sigma projects (Correct answer)
- Trains Green Belts and Black Belts in statistical methods
- Manages the project budget only
Correct answer: A senior leader who sponsors and removes barriers for Six Sigma projects
Champions are senior managers who select, sponsor, and support Six Sigma projects, ensure resources are available, and break down organizational barriers.
Lean Six Sigma Green Belt Certification Prep 4
What is a 'Kaizen event' in Lean Six Sigma?