There are basically two tables. The first one tells you which ‘code letter’ to use. Then, the code letter will give you the sample size and the maximum number of defects that can be accepted.

Professionals in the quality control field have been using AQL as the basis for acceptance sampling for decades. Sometimes it’s desirable to inspect an entire order of goods. But in most cases, you’ll benefit more by having inspection staff pull a random sample of units from the total order to check using AQL.

The acceptable quality level (AQL) is a measure applied to products and defined in ISO 2859-1 as the “quality level that is the worst tolerable.”