Lean Six Sigma Black Belt Certification FREE Basic Lean Six Sigma Black Belt Certification Questions and Answers 2 — Questions and Answers
Question 1: What is the primary purpose of a SIPOC diagram in the Define phase of a DMAIC project?
- To provide a high-level overview of the process including suppliers, inputs, process steps, outputs, and customers (Correct answer)
- To calculate the sigma level of the current process
- To identify the root cause of defects
- To establish control limits for process monitoring
Correct answer: To provide a high-level overview of the process including suppliers, inputs, process steps, outputs, and customers
A SIPOC diagram maps Suppliers, Inputs, Process, Outputs, and Customers to give stakeholders a high-level understanding of the process scope.
Question 2: In hypothesis testing, what does a Type II error represent?
- Rejecting a true null hypothesis
- Failing to reject a false null hypothesis (Correct answer)
- Accepting an alternative hypothesis correctly
- Rejecting a false null hypothesis
Correct answer: Failing to reject a false null hypothesis
A Type II error (beta error) occurs when the test fails to detect a real difference, meaning a false null hypothesis is not rejected.
Question 3: Which tool is most appropriate for identifying the vital few causes from the trivial many in a Six Sigma project?
- Control chart
- Pareto chart (Correct answer)
- Histogram
- Run chart
Correct answer: Pareto chart
A Pareto chart applies the 80/20 principle to visually separate the vital few causes that account for most of the variation from the trivial many.
Question 4: What does Cp measure in process capability analysis?
- The potential capability of a process when centered between specification limits (Correct answer)
- The actual capability of a process accounting for centering
- The long-term defect rate of a process
- The short-term variation relative to the mean
Correct answer: The potential capability of a process when centered between specification limits
Cp measures potential process capability by comparing the specification width to the process spread, assuming the process is perfectly centered.
Question 5: During the Analyze phase, a Black Belt discovers strong multicollinearity among predictor variables in a regression model. What is the most appropriate action?
- Increase the sample size to reduce the effect
- Remove one or more correlated predictors or use principal component analysis (Correct answer)
- Ignore it since it does not affect prediction accuracy
- Switch to a non-parametric test
Correct answer: Remove one or more correlated predictors or use principal component analysis
Multicollinearity inflates coefficient variance and makes individual predictor effects unreliable, so removing redundant predictors or using dimensionality reduction is the standard remedy.
Question 6: What is the key difference between a cause-and-effect matrix and a Failure Mode and Effects Analysis (FMEA)?
- A cause-and-effect matrix prioritizes inputs against outputs while FMEA evaluates risk using severity, occurrence, and detection ratings (Correct answer)
- A cause-and-effect matrix is used only in the Control phase while FMEA is used in Define
- FMEA is a qualitative tool while the cause-and-effect matrix is purely quantitative
- There is no difference; they are interchangeable tools
Correct answer: A cause-and-effect matrix prioritizes inputs against outputs while FMEA evaluates risk using severity, occurrence, and detection ratings
The cause-and-effect matrix ranks process inputs by their impact on key outputs, while FMEA assigns severity, occurrence, and detection scores to calculate a Risk Priority Number.
Lean Six Sigma Black Belt Certification FREE Basic Lean Six Sigma Black Belt Certification Questions and Answers 2
What is the primary purpose of a SIPOC diagram in the Define phase of a DMAIC project?