Module 12 · Lesson 11 of 14
Mixed DMAIC scenario set
This lesson and the entire Lean Six Sigma Black Belt academy are free of charge — no fees, ever.
Learning objectives
- Diagnose the correct DMAIC phase for typical garment situations.
- Match a tool to a symptom without reaching for statistics first.
- Practice the reasoning expected in the final examination.
How to approach mixed scenarios
The trap in mixed scenarios is to leap to a favourite tool. The disciplined move is to name the DMAIC phase the situation is really in, then choose a tool from that phase.
Every quiz question below has one strongest answer and one plausible distractor. The explanation tells you why the strong answer wins.
Garment-factory example
A production manager reports rising DHU on a denim line during the last two weeks. A junior belt suggests a Kaizen event. The correct move is to reopen Measure: confirm the DHU calculation, check the operational definition of “defect” and run a stability check before assuming a special cause.
Method
- Read the scenario twice before choosing an answer.
- Ask “what evidence is missing?” instead of “what is the solution?”
- Match the phase first, then the tool.
Common mistakes
- Reaching for a t-test when the operational definition is unclear.
- Skipping to Improve before a baseline exists.
Knowledge check
Pick one answer per question. Explanations appear after you submit.
1. A team says the line “feels slower” after a new folder was installed. Which DMAIC action is best?
2. Buyer QA rejects a shipment for shade. The team wants to run a Kaizen. What comes first?
Author: NOSK.life · Last reviewed: 2026-07-21