Lean Six Sigma Green Belt Practice Exam — All Questions
3 questions
A designed experiment (DOE) that studies two factors, each at two levels, in every combination is called a:
- a.One-factor-at-a-time (OFAT) study
- b.Full factorial 2^2 design✓
- c.Fractional factorial design
- d.Simple linear regression
Testing every combination of 2 factors at 2 levels each is a full factorial 2^2 design (four runs). Changing one factor at a time is OFAT, and a fractional factorial deliberately runs only a subset of the combinations.
Poka-yoke, applied in the Improve phase, refers to:
- a.A statistical sampling plan
- b.A capacity-planning calculation
- c.Mistake-proofing that prevents or immediately detects errors✓
- d.A supplier scorecard
Poka-yoke is error- or mistake-proofing that makes a defect impossible or obvious, such as a connector that only fits one way. It is a prevention technique, not a sampling, capacity, or supplier-rating method.
A process has available production time of 480 minutes per shift and customer demand of 240 units per shift. What is the takt time?
- a.0.5 minutes per unit
- b.480 minutes per unit
- c.240 minutes per unit
- d.2 minutes per unit✓
Takt time = available time / customer demand = 480 / 240 = 2 minutes per unit, the pace needed to meet demand. Inverting the ratio or ignoring demand gives the wrong result.