As commonly known in the international trade, “AQL” stands for Acceptable Quality Limit. The “AQL tables” represent the industry standard and therefore are important statistical tools used by buyers for product inspections.
The “AQL tables” help to gauge two key areas:-
How many samples out of a batch of products should be picked and inspected?
What is the limit for a batch of products containing certain defects to still be regarded as acceptable?
In practice, defects are categorised into three groups, namely, “Critical”, “Major ” and “Minor” and they in turn mean:-
Critical: Defects which could result in hazardous or unsafe conditions for individuals using or maintaining the product as well as defects contravening legal regulations.
Major: Functional defects reducing the usability or solidity of the product as well as obvious visual defects reducing the sales value of the product.
Minor: Defects that are unlikely to reduce the use of the product, but nevertheless may influence the sale.
The limit differs for different markets of products or according to the functionalities of the products. For instance, parts and fittings used in constructing aircrafts are subject to a much more stringent (lower) AQL.
So, the question for the bag manufacturing industry is – what is the common AQL for bags? Put simply, the common inspection level is “level II” and the most commonly used proportion for bags is as follows:-
Critical defect: 0.01
Major defect : 2.5
Minor defect : 4.0
The relevant AQL table looks like this:
This means, for example, when the production lot size is in between 1201-3200 pieces, the quantity to be picked and inspected should be 125 pieces. No more than 7 major defects and 10 minor defects should be found during the inspection, otherwise the result of this inspection will be considered as fail/rejected.