Critical-to-quality requirements

Learning objectives

• Translate VOC into measurable CTQs.
• Define units, specifications and defect criteria.
• Separate metric from specification from capability.

From feeling to number

"Good fit" is not measurable. It must decompose into garment points of measure, tolerance, grade consistency and measurement method before it becomes a CTQ.

Garment-factory example

"No shade variation" becomes an approved shade standard, a specified visual/instrumental method, a light source, a lot rule and an acceptance limit.

Method

1. Select the customer need.
2. Ask what drives it.
3. Define the metric and specification.
4. Validate the CTQ with the customer or technical authority.

Common mistakes

• Choosing metrics because data already exist.
• Leaving subjective terms undefined.