ASQ Six Sigma Green Belt 5 — Questions and Answers
Question 1: Which of the following best defines 'takt time' in lean manufacturing?
- The actual cycle time required to complete one unit
- The available production time divided by customer demand rate (Correct answer)
- The time from order placement to order delivery
- The time a product spends waiting between process steps
Correct answer: The available production time divided by customer demand rate
Takt time is the pace of production needed to meet customer demand, calculated as available production time divided by the number of units demanded.
Question 2: When performing a regression analysis, what does the R-squared (R²) value tell you?
- The slope of the regression line
- The proportion of variation in Y explained by the X variable(s) (Correct answer)
- Whether the regression model is statistically significant
- The number of data points needed for a valid model
Correct answer: The proportion of variation in Y explained by the X variable(s)
R² measures the proportion of total variation in the response variable that is accounted for by the predictor variables in the regression model.
Question 3: A Green Belt is analyzing defect data across five product lines using a chi-square test. What type of null hypothesis is being tested?
- The mean defect rates are equal across all five product lines
- The defect proportions are independent of (not associated with) product line (Correct answer)
- The standard deviations of defect counts are equal across product lines
- The distribution of defects is normal for all five product lines
Correct answer: The defect proportions are independent of (not associated with) product line
A chi-square test of independence tests whether there is a significant association between two categorical variables — in this case, product line and defect occurrence.
Question 4: What is the difference between 'precision' and 'accuracy' in a measurement system?
- Accuracy refers to consistency of repeated measurements; precision refers to closeness to the true value
- Precision refers to consistency of repeated measurements; accuracy refers to closeness to the true value (Correct answer)
- Precision and accuracy are interchangeable terms in measurement systems analysis
- Accuracy is measured by Gage R&R while precision is measured by calibration
Correct answer: Precision refers to consistency of repeated measurements; accuracy refers to closeness to the true value
Precision (repeatability/reproducibility) describes how consistently a system measures the same item; accuracy describes how close measurements are to the true reference value.
Question 5: In a full factorial 2^3 DOE with factors A, B, and C, how many experimental runs are required (excluding replicates)?
- 3
- 6
- 8 (Correct answer)
- 9
Correct answer: 8
A full factorial 2^3 design tests 3 factors each at 2 levels, requiring 2³ = 8 experimental runs to evaluate all factor combinations.
Question 6: Which of the following is an example of a 'poka-yoke' (mistake-proofing) device?
- A statistical process control chart posted at the workstation
- A USB connector that can only be inserted in one orientation (Correct answer)
- An operator checklist for part inspection
- A training program for new assembly line workers
Correct answer: A USB connector that can only be inserted in one orientation
A USB connector designed to fit only one way is a physical poka-yoke that prevents incorrect assembly without relying on operator attention or skill.
Question 7: In the DMAIC framework, which phase is responsible for quantifying the financial and operational impact of the improvement on the business?
- Define
- Measure
- Analyze
- Control (Correct answer)
Correct answer: Control
The Control phase validates sustained improvement and quantifies the realized financial and operational benefits, closing the loop on the project's business impact.
ASQ Six Sigma Green Belt 5
Which of the following best defines 'takt time' in lean manufacturing?