AQL is the worst average defect rate that a sampling plan is designed to accept most of the time. Instead of checking every part, the inspector pulls a sample whose size depends on the lot size and the inspection level, then counts defects. If the count is at or below the accept number, the lot passes; at or above the reject number, it fails. The tables behind this come from sampling standards such as ISO 2859-1 and the older MIL-STD-105. AQL is not a promise that a passed lot has that defect rate.
Example: A lot of 1,200 parts is inspected at general inspection level II, normal inspection, AQL 1.0. The plan gives code letter J: sample 80 parts, accept the lot with 2 or fewer defectives, reject it with 3 or more.
Sampling saves inspection time, but only when everyone agrees on the plan. Receiving and final inspection should state the AQL, level and plan on the work instruction, so two inspectors make the same call on the same lot. A lot that passes can still hold defects, so critical features usually need 100% checks or zero-acceptance plans.
COPLAIN AI PLATFORM
Upload your existing procedures and Coplain AI drafts audit-ready work instructions, job aids and forms from them.
Generate yours automatically with Coplain →Related Tools & Templates