Lean Six Sigma Black Belt Certification Define and Measure Phases 5 — Questions and Answers
Question 1: A team performs an attribute agreement analysis and finds that appraisers agree with each other 72% of the time but agree with the standard only 60% of the time. What should the team do first?
- Accept the measurement system as adequate
- Recalibrate the gauge
- Investigate and standardize the appraisal criteria and training (Correct answer)
- Increase the sample size
Correct answer: Investigate and standardize the appraisal criteria and training
Low agreement with the standard indicates poor accuracy; the team should clarify criteria, retrain appraisers, and rerun the study before collecting process data.
Question 2: Which metric captures the percentage of time a process produces output without any defects, rework, or scrap on the first attempt?
- Overall Equipment Effectiveness (OEE)
- First Pass Yield (FPY) (Correct answer)
- Defects Per Million Opportunities (DPMO)
- Rolled Throughput Yield (RTY)
Correct answer: First Pass Yield (FPY)
First Pass Yield (FPY) measures the proportion of units that complete the process correctly the first time without any rework.
Question 3: A project team calculates Rolled Throughput Yield (RTY) for a 4-step process with individual step yields of 95%, 92%, 98%, and 90%. What is the approximate RTY?
- 93.75%
- 77.0% (Correct answer)
- 81.4%
- 90.0%
Correct answer: 77.0%
RTY is the product of all step yields: 0.95 × 0.92 × 0.98 × 0.90 ≈ 0.770, showing how hidden rework dramatically reduces true throughput yield.
Question 4: In a SIPOC diagram, which column directly feeds into the process steps column?
- Suppliers
- Inputs (Correct answer)
- Outputs
- Customers
Correct answer: Inputs
Inputs (materials, information, resources) are what enter each process step and are supplied by the Suppliers column to the left.
Question 5: A Black Belt selects a sample size for a baseline capability study. The primary driver of minimum sample size is ensuring which of the following?
- At least 30 observations per subgroup
- Sufficient statistical power to detect meaningful shifts (Correct answer)
- A balanced design across all shifts
- Equal representation of all operators
Correct answer: Sufficient statistical power to detect meaningful shifts
Sample size must be large enough to provide adequate statistical power to detect the difference or capability level of practical importance.
Question 6: A value stream map is created in the Measure phase. Which metric represents the ratio of value-added time to total lead time?
- Takt time
- Process cycle efficiency (PCE) (Correct answer)
- Overall Equipment Effectiveness
- Pitch
Correct answer: Process cycle efficiency (PCE)
Process Cycle Efficiency (PCE) = Value-Added Time ÷ Total Lead Time, and is used to quantify the proportion of time the process spends adding value.
Question 7: During the Measure phase, a team uses a check sheet to collect data. What is the primary purpose of a check sheet?
- Determine root causes of defects
- Display process variation over time
- Systematically collect and tally defect or event data (Correct answer)
- Prioritize improvement opportunities
Correct answer: Systematically collect and tally defect or event data
Check sheets provide a structured, easy-to-use form for recording and tallying data as events occur, ensuring consistent data collection.
Lean Six Sigma Black Belt Certification Define and Measure Phases 5
A team performs an attribute agreement analysis and finds that appraisers agree with each other 72% of the time but agree with the standard only 60% of the time.
What should the team do first?