AQL (Acceptable Quality Limit)

AQL (Acceptable Quality Limit) is a widely used sampling inspection standard in international trade to determine whether a batch of products is acceptable. It defines the worst tolerable process average quality level in sampling inspection, meaning that when the defective rate is below the AQL, the batch should be accepted; when above the AQL, it should be rejected. AQL is usually used in conjunction with standards such as ISO 2859 or GB/T 2828.1, and is suitable for inspection of continuous batches, such as in the apparel, electronics, and toy industries. Usage scenarios include: the buyer and seller agree on a sampling plan (sample size, acceptance number, rejection number), and the inspector conducts sampling inspection according to the AQL value and makes an accept or reject decision. Notes: AQL is not the allowed defective rate, but a quality upper limit; different defect classes (critical, major, minor) can have different AQL values; AQL is not applicable to isolated batches or destructive testing. Unlike 'LTPD' (Lot Tolerance Percent Defective), AQL focuses on the producer's risk, while LTPD focuses on the consumer's risk. In addition, AQL is similar to the concept of 'acceptable quality level,' but places more emphasis on the acceptable upper limit.