Inspection Plans
An inspection plan is the list of checks an inspector actually performs. Item quality settings decide whether an item is inspected and how many units are sampled; the plan decides what is looked at on each one. Without a plan an inspection still records a quantity and a verdict — with one, it records evidence.
A plan row
| Field | Notes |
|---|---|
| Item / Category | What the check applies to. A category covers everything in it. |
| Check | The characteristic being checked, in the inspector's words — Diameter, Appearance, Weight. |
| Check Type | A measurement, which asks for readings, or an attribute, which is a plain pass or fail. |
| Specification | The target with its lower and upper limits, for a measurement. |
| Criticality | Critical, Major or Minor. Critical is accepted at zero under AQL. |
| Method | How to perform the check. |
| Gauge Type | Which kind of instrument to use — Vernier caliper. Ties the check to calibrated equipment. |
| Readings | How many readings the check wants. The inspection form draws that many boxes. |
| Applies To | Which documents the check runs on: all, production, incoming goods or outgoing goods. |
| Order | The sequence the checks are listed in on the inspection form. |
| Inactive | Retires the check without losing the inspections already recorded against it. |
Measurements and attributes
The distinction matters more than it looks. A measurement produces numbers, which means it can be plotted and its capability calculated — see SPC. An attribute produces a verdict only. Where a number is available, record the number; you can always reduce it to pass or fail later, but you cannot recover a measurement you never took.
Scope with Applies To
The same item is often checked differently on the way in and on the way out. Applies To lets one item carry both: a dimensional check scoped to Incoming Goods, a packaging check scoped to Outgoing Goods, and a check scoped to All that runs on everything. The inspection form shows only the checks in scope for the document being inspected.
Criticality
| Class | Under AQL |
|---|---|
| Critical | Accepted at zero. One in the sample rejects the lot, whatever the AQL says. |
| Major | Judged against the item's major AQL. |
| Minor | Judged against the item's minor AQL. |
Classing everything Critical looks rigorous and works badly: every lot with a single cosmetic blemish is rejected, holds pile up, and people start working around the system. Reserve Critical for what genuinely cannot ship.