From approved sample to delivered lot: writing an acceptance standard that holds

The sample is a reference, not a specification

A physical sample answers what the thing looks like. It cannot answer how much variation is acceptable, so it must be converted into a written standard with measured values and tolerances before the first production run.

What the standard should contain

External and internal dimensions with tolerance; wall thickness at named points; latch and hinge operation force; gasket compression; colour reference with the tolerance method; liner pocket dimensions; the drop or stack test to be repeated on production samples; packaging configuration; and the marking and labelling layout.

Sampling plan and AQL

State the inspection level, the AQL for critical, major and minor defects, and what counts as each. Cosmetic scuffing on a surface that faces a wall is not the same defect class as a latch that does not seat. Without that split, every report becomes an argument.

Golden sample custody

Keep two signed samples, one with you and one with the plant, both dated and marked. Photograph the marking. Most batch-does-not-match-sample disputes are actually a dispute about which sample was the reference.

Decide the remedy before you need it

Specify what happens on a failed inspection: rework at the supplier cost with re-inspection, sorting with a discount, or rejection with a refund of the deposit. The option you do not write down is the option you will not get.

Questions buyers ask