Certified Six Sigma Black Belt Exam Basic 2 — Questions and Answers
Question 1: Which of the following best describes the purpose of a control chart in Six Sigma?
- To identify the root cause of defects
- To monitor process variation over time and detect special causes (Correct answer)
- To rank defects by frequency of occurrence
- To map the flow of a process from start to finish
Correct answer: To monitor process variation over time and detect special causes
Control charts monitor process variation over time to distinguish between common cause (natural) variation and special cause (assignable) variation.
Question 2: In DMAIC, the 'Analyze' phase primarily focuses on:
- Collecting baseline process data
- Implementing permanent corrective actions
- Identifying root causes of the problem (Correct answer)
- Establishing control mechanisms
Correct answer: Identifying root causes of the problem
The Analyze phase uses data and statistical tools to identify and verify the root causes contributing to the problem.
Question 3: What does 'Cp' measure in process capability analysis?
- The centering of the process relative to specifications
- The potential capability assuming the process is centered (Correct answer)
- The actual process performance including defects
- The spread of the process mean over time
Correct answer: The potential capability assuming the process is centered
Cp measures the potential capability of a process by comparing the specification width to the process spread, assuming the process is perfectly centered.
Question 4: A Pareto chart is based on which principle?
- 80% of effects come from 20% of causes (Correct answer)
- Variation is always normally distributed
- 50% of defects are random in nature
- All causes contribute equally to defects
Correct answer: 80% of effects come from 20% of causes
The Pareto principle (80/20 rule) states that roughly 80% of problems stem from 20% of causes, guiding teams to focus on the vital few issues.
Question 5: Which metric directly measures the probability of producing a defect-free unit at every step of a multi-step process?
- Defects Per Million Opportunities (DPMO)
- Rolled Throughput Yield (RTY) (Correct answer)
- First Pass Yield (FPY)
- Process Sigma Level
Correct answer: Rolled Throughput Yield (RTY)
Rolled Throughput Yield (RTY) multiplies the yield of each process step together, reflecting the true probability that a unit passes all steps without a defect.
Question 6: When a process has a sigma level of 6, its DPMO is approximately:
- 66,807
- 3,400
- 233
- 3.4 (Correct answer)
Correct answer: 3.4
A Six Sigma process produces approximately 3.4 defects per million opportunities, accounting for a 1.5-sigma long-term shift.
Question 7: What is the primary role of a Six Sigma Black Belt?
- Approving project budgets and resource allocation
- Leading complex cross-functional improvement projects full-time (Correct answer)
- Training executives on Six Sigma concepts
- Performing daily quality inspections on the production floor
Correct answer: Leading complex cross-functional improvement projects full-time
A Six Sigma Black Belt leads complex improvement projects full-time, applying advanced statistical tools and mentoring Green Belts.
Certified Six Sigma Black Belt Exam Basic 2
Which of the following best describes the purpose of a control chart in Six Sigma?