Translating the problem into a measurable project Y

Learning objectives

• Translate a Define problem into a single measurable project Y.
• State the Y as a variable with unit, scale and observation rule.
• Distinguish the primary Y from secondary and guardrail metrics.

From problem to Y

The project Y is the response the team will move. It must be observable at the frequency the process actually runs and traceable to the customer CTQ agreed in Define.

A vague Y such as ‘quality’ is unmeasurable. ‘Chest-width deviation in cm at final inspection per garment’ is measurable, has a unit and a clear observation rule.

Garment-factory example

A polo project restates ‘too many rejects’ as Y = defects per hundred units (DHU) recorded at end-of-line by shift, style and line, with the operational defect list frozen for the study.

Method

1. Rewrite the problem as ‘Y = … measured in … at … per …’.
2. Confirm the Y links to a customer CTQ, not only internal cost.
3. List one or two guardrails that must not deteriorate.
4. Freeze definitions before baseline collection begins.

Common mistakes

• Choosing several primary Ys that later contradict each other.
• Changing the Y definition mid-baseline to improve the number.