AQL is a widely used term in apparel product inspection. 100% inspection of finished garments is not performed. Instead, sample-based inspection is preferred for apparel products. Mostly AQL system is followed at the final shipment inspection. That is prior to shipping an export order. Though suppliers can follow the AQL system (sampling type and AQL level) for the internal audits.
It means in a sample-based product inspection system, how minimum defectives goods are acceptable in a purchase order as per the contract with a customer.
At present, when a customer imports goods from other countries follow sample-based inspection, that is AQL. To use AQL-based inspection, auditors use AQL Chart that is originated from ANSI. A sample of the AQL Chart is shown in this post.
In most cases, apparel suppliers get AQL level and sample type to be followed in the final inspection from their buyers. The final decision of shipment acceptance depends on the inspection result assessed based on the AQL.