Lean Six Sigma Yellow Belt Certification Prep 3

Question 1

A process produces 20 defects per 1,000 opportunities. What is the DPMO?

Accepted Answer

20,000

Answer

DPMO = (defects / opportunities) × 1,000,000 = (20/1,000) × 1,000,000 = 20,000 DPMO.

Question 2

Which of the following best describes 'poka-yoke'?

Accepted Answer

An error-proofing mechanism that prevents or detects defects

Answer

Poka-yoke refers to any mistake-proofing device or method designed to prevent errors or make defects immediately obvious.

Question 3

What is the purpose of a Measurement System Analysis (MSA)?

Accepted Answer

To assess whether the measurement system introduces significant variation into the data

Answer

MSA (often a Gage R&R study) evaluates how much of the observed variation comes from the measurement system itself versus the actual process.

Question 4

In Lean thinking, 'overproduction' is considered waste because:

Accepted Answer

It produces more than the customer currently needs, consuming resources and creating inventory

Answer

Overproduction is the worst Lean waste as it drives all other wastes — excess inventory, extra transportation, unnecessary motion, and storage costs.

Question 5

A Yellow Belt notices a process step takes 45 minutes but only 5 minutes of that adds value to the customer. What Lean metric captures this ratio?

Accepted Answer

Process cycle efficiency (PCE)

Answer

Process Cycle Efficiency = Value-Added Time / Total Lead Time; here PCE = 5/45 ≈ 11%, indicating significant waste.

Lean Six Sigma Yellow Belt Certification Practice Test