Certified Six Sigma Black Belt Exam Basic 3 — Questions and Answers
Question 1: Which tool is used in the 'Define' phase to capture the voice of the customer and link it to critical quality characteristics?
- Failure Mode and Effects Analysis (FMEA)
- Quality Function Deployment (QFD) (Correct answer)
- Statistical Process Control (SPC)
- Design of Experiments (DOE)
Correct answer: Quality Function Deployment (QFD)
QFD (the House of Quality) translates customer needs (VOC) into measurable technical requirements and critical-to-quality characteristics.
Question 2: In a hypothesis test, Type II error (β) occurs when:
- A true null hypothesis is rejected
- A false null hypothesis is failed to be rejected (Correct answer)
- The sample size is too large
- The p-value exceeds the significance level
Correct answer: A false null hypothesis is failed to be rejected
A Type II error is failing to reject a null hypothesis that is actually false — also called a 'false negative' or missing a real effect.
Question 3: What does an Ishikawa (fishbone) diagram help identify?
- The frequency distribution of defects
- Potential causes contributing to a specific effect or problem (Correct answer)
- The sequence of process steps and decision points
- The relationship between two continuous variables
Correct answer: Potential causes contributing to a specific effect or problem
An Ishikawa diagram organizes potential causes (often grouped as 6Ms) to systematically identify root causes of a problem.
Question 4: Gauge Repeatability and Reproducibility (GR&R) studies evaluate:
- Whether a process is in statistical control
- The capability of a measurement system to produce consistent results (Correct answer)
- The relationship between input and output variables
- The cost of poor quality in a process
Correct answer: The capability of a measurement system to produce consistent results
A GR&R study quantifies measurement system variation from repeatability (same operator, same gauge) and reproducibility (different operators) to assess whether the measurement system is adequate.
Question 5: Which statistical test is appropriate for comparing the means of three or more independent groups?
- Paired t-test
- One-sample t-test
- One-way ANOVA (Correct answer)
- Chi-square test
Correct answer: One-way ANOVA
One-way ANOVA (Analysis of Variance) tests whether the means of three or more independent groups are statistically equal.
Question 6: In Six Sigma, 'entitlement' refers to:
- The minimum performance a process must achieve to meet specifications
- The best short-term performance a process has ever demonstrated (Correct answer)
- The long-term process average after all improvements
- The performance level mandated by customer contracts
Correct answer: The best short-term performance a process has ever demonstrated
Entitlement is the best short-term performance a process has achieved, representing the theoretical capability without changing the fundamental process design.
Question 7: A process produces 150 defects across 5,000 units with 3 opportunities per unit. What is the DPMO?
- 30,000
- 10,000 (Correct answer)
- 50,000
- 5,000
Correct answer: 10,000
DPMO = (Defects / (Units × Opportunities)) × 1,000,000 = (150 / (5,000 × 3)) × 1,000,000 = 10,000.
Certified Six Sigma Black Belt Exam Basic 3
Which tool is used in the 'Define' phase to capture the voice of the customer and link it to critical quality characteristics?