Lean Six Sigma Black Belt Certification Basic 4 — Questions and Answers
Question 1: Which risk priority ranking method used in FMEA multiplies Severity, Occurrence, and Detection ratings together?
- DPMO score
- Risk Priority Number (RPN) (Correct answer)
- Cpk index
- Z-score
Correct answer: Risk Priority Number (RPN)
The Risk Priority Number (RPN) = Severity × Occurrence × Detection, and is used to prioritize failure modes for corrective action in FMEA.
Question 2: A scatter plot shows a correlation coefficient (r) of −0.92. What does this indicate?
- Weak positive relationship
- Strong positive relationship
- Strong negative relationship (Correct answer)
- No linear relationship
Correct answer: Strong negative relationship
A correlation coefficient of −0.92 indicates a strong negative linear relationship — as one variable increases, the other decreases substantially.
Question 3: Which Lean tool uses visual signals (cards or bins) to authorize and trigger production or material replenishment?
- 5S
- Kanban (Correct answer)
- Poka-yoke
- Andon
Correct answer: Kanban
Kanban is a pull-based scheduling system that uses visual signals to authorize replenishment of materials or production only when needed.
Question 4: In regression analysis, what does R² (coefficient of determination) measure?
- The slope of the regression line
- The proportion of variance in Y explained by X (Correct answer)
- The correlation between residuals and fitted values
- The significance level of the model
Correct answer: The proportion of variance in Y explained by X
R² represents the proportion of the total variance in the response variable (Y) that is explained by the predictor variable(s) in the regression model.
Question 5: The concept of 'Design for Six Sigma' (DFSS) is most closely associated with which methodology?
- DMAIC
- PDCA
- DMADV (Correct answer)
- SIPOC
Correct answer: DMADV
DMADV (Define, Measure, Analyze, Design, Verify) is the DFSS methodology used to design new products or processes to Six Sigma capability from the start.
Question 6: Which type of control chart is used to monitor the proportion of nonconforming units in a process with variable subgroup sizes?
- p-chart (Correct answer)
- np-chart
- c-chart
- u-chart
Correct answer: p-chart
The p-chart monitors the proportion (fraction) of nonconforming units and accommodates variable subgroup sizes, unlike the np-chart which requires constant subgroup size.
Question 7: A Black Belt applies a control plan after implementing process improvements. Which element is NOT typically included in a control plan?
- Control method and frequency
- Reaction plan for out-of-control conditions
- Financial ROI of the project (Correct answer)
- Measurement system used
Correct answer: Financial ROI of the project
A control plan documents what to measure, how to measure it, frequency, and reaction plans — financial ROI belongs in the project charter or business case, not the control plan.
Lean Six Sigma Black Belt Certification Basic 4
Which risk priority ranking method used in FMEA multiplies Severity, Occurrence, and Detection ratings together?