Six Sigma Green Belt Flashcards

Which of the following best defines 'takt time' in lean manufacturing?

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.

When performing a regression analysis, what does the R-squared (R²) value tell you?

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.

A Green Belt is analyzing defect data across five product lines using a chi-square test. What type of null hypothesis is being tested?

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.

What is the difference between 'precision' and 'accuracy' in a measurement system?

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.

In a full factorial 2^3 DOE with factors A, B, and C, how many experimental runs are required (excluding replicates)?

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.

Which of the following is an example of a 'poka-yoke' (mistake-proofing) device?

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.

In the DMAIC framework, which phase is responsible for quantifying the financial and operational impact of the improvement on the business?

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.