Mixed DMAIC scenario set

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

1. Read the scenario twice before choosing an answer.
2. Ask “what evidence is missing?” instead of “what is the solution?”
3. 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.