One person's B-grade is another's rejection

Every textile operation produces some output below first quality. The proportion is a real measure of process health, and it is only a measure if grading means the same thing on Tuesday as it did on Monday.

Grade without reason is not data

Recording that a piece is B-grade tells you the outcome. Recording why — a specific defect type — tells you where it came from, and only the second one can be acted on.

Tracing back

Defects concentrated on a machine or a shift are a maintenance or training question. Defects spread evenly are a materials or specification question. Without the trace, both look like a general quality problem and get a general response.

Seconds are inventory

Sub-standard output has a market. Units that treat it as waste dispose of it cheaply and irregularly; units that grade and hold it sell it as a category with its own pricing, which frequently covers more than the cost of running the inspection properly.