QC Profile

Suggestion on AQL Levels


Critical Defects



Major Defects



Minor Defects



Understanding AQL

How do I determine the right sample size and acceptance number?

As an example, in an inspection of a 3,500 unit lot, with an Acceptable Quality Level of II, Table A indicates that sample size code letter should be "L" . Table B indicates that the sampling size of "L" should be 200 units. For an AQL of 2.5, the corresponding acceptance number is 10.

What does this mean in concrete terms?

If the number of defective units is higher than 10, the lot should be rejected. It also means that, if the lot passes inspection, there is a 95% chance that less than 5% (10 defects in this example) of the entire inspected lot will be defective.

What should I do with defective or discarded lots?

Defective items found as part of 100% inspection can be discarded, repaired or replaced. You may opt to buy the discarded lot at a discount for resale at a lower price.

Defects detected during visual inspections are classified into three categories as follows:

Critical Defect:

Critical Defect corresponds to a defect likely to be unsafe for consumers. Our default Critical Defect AQL is Not Allowed.

Major Defect:

Major Defect results in function failures or reduction of product usability or obvious appearance faults which may affect the salability of the product. Our default Major Defect AQL is 2.5.

Minor Defect:

Minor Defect doesn't reduce the usability or function of the product, but is beyond the defined quality standard and may reduce the salability of the product. Our default Minor Defect AQL is 4.0.

Clients can also specify what points are Minor, Major or Critical in their own checklists.