Certified Six Sigma Black Belt Exam Voice of the Customer (VOC) 3 — Questions and Answers
Question 1: A Critical-to-Quality (CTQ) characteristic is best described as which of the following?
- An internal process metric set by engineering
- A measurable product or service feature directly linked to a customer requirement (Correct answer)
- A financial target set by senior management
- A defect category identified in an FMEA
Correct answer: A measurable product or service feature directly linked to a customer requirement
CTQs are measurable characteristics of a product or process that are critical to satisfying the customer's needs.
Question 2: In the CTQ drill-down tree, what is the correct sequence from customer need to specification?
- CTQ → Quality Driver → Customer Need
- Customer Need → Quality Driver → CTQ (Correct answer)
- Quality Driver → Customer Need → CTQ
- CTQ → Customer Need → Quality Driver
Correct answer: Customer Need → Quality Driver → CTQ
The CTQ tree flows from broad customer need, to quality driver (theme), to specific measurable CTQ.
Question 3: Which VOC technique involves observing customers in their natural environment to discover unarticulated needs they cannot describe in a survey?
- Conjoint analysis
- Ethnographic research (Correct answer)
- Regression analysis
- Benchmarking
Correct answer: Ethnographic research
Ethnographic research (contextual observation) reveals tacit needs by watching customers use a product in their real context.
Question 4: A Black Belt conducts a customer survey and finds that question ordering caused respondents to rate later items more negatively. This is an example of which bias?
- Confirmation bias
- Response bias due to question order (context effect) (Correct answer)
- Sampling bias
- Interviewer bias
Correct answer: Response bias due to question order (context effect)
Context effect (order bias) occurs when earlier survey questions prime respondents and distort ratings on subsequent questions.
Question 5: When using affinity diagrams to organize VOC data, what is the primary purpose of the grouping exercise?
- To rank customer needs by frequency
- To identify natural clusters of related customer needs or themes (Correct answer)
- To calculate sigma levels for each requirement
- To assign ownership of each customer complaint
Correct answer: To identify natural clusters of related customer needs or themes
Affinity diagrams organize large volumes of qualitative VOC data into meaningful thematic clusters to reveal patterns.
Question 6: A company uses warranty data as a proxy for VOC. Which limitation must the Black Belt account for?
- Warranty data is always statistically insignificant
- Only a small fraction of dissatisfied customers file warranty claims (Correct answer)
- Warranty data cannot be stratified by customer segment
- Warranty claims cannot be converted to CTQs
Correct answer: Only a small fraction of dissatisfied customers file warranty claims
Research shows that most dissatisfied customers do not complain formally, so warranty data systematically underrepresents actual dissatisfaction.
Question 7: In QFD's House of Quality, what does the 'roof' (correlation matrix) represent?
- The relationship between customer needs and technical requirements
- The trade-offs and interactions among technical requirements (Correct answer)
- The competitive benchmarking scores
- The importance weighting of customer needs
Correct answer: The trade-offs and interactions among technical requirements
The roof of the House of Quality identifies positive, negative, or strong correlations between technical characteristics to flag trade-offs.
Certified Six Sigma Black Belt Exam Voice of the Customer (VOC) 3
A Critical-to-Quality (CTQ) characteristic is best described as which of the following?