Inspection and testing
ISO 2859-1: Sampling procedures for inspection by attributes, sampling schemes indexed by AQL
The most widely used basis for sampling inspection. Understanding what an AQL does and does not guarantee is essential for buyers.
Reference noteThis page is an independent plain-language summary written by QUALITAS TR. It does not reproduce the standard. Always work from the current official edition, available from ISO, the International Organization for Standardization, and national standards bodies such as TSE in Turkey (official page). QUALITAS TR supports organisations against this standard; it does not certify them.
01Purpose
ISO 2859-1 specifies an acceptance sampling system for inspection by attributes, indexed by acceptance quality limit (AQL). It is intended for a continuing series of lots.
02Scope
Applies to inspection of end items, components, raw materials and other products where results are recorded as conforming or nonconforming, or number of nonconformities.
03Main requirements
- Lot size and inspection level determine a sample size code letter
- AQL and code letter determine sample size and acceptance and rejection numbers
- Single, double and multiple sampling plans
- Normal, tightened and reduced inspection with switching rules
- Classification of nonconformities into classes with different AQLs
04Typical applications and industries
Pre-shipment inspection, incoming inspection and final inspection of series products. Try our AQL calculator.
05Audit and inspection considerations
- Is the AQL defined for each defect class?
- Are defect definitions agreed, not only the AQL?
- Is the sample drawn randomly from the whole lot?
06Common nonconformities
- AQL applied without defined defect criteria
- Sample taken only from accessible cartons
- Switching rules ignored for long running supply
- AQL misunderstood as maximum permitted defect rate
07How QUALITAS TR can support
We apply ISO 2859-1 in pre-shipment and quality control inspections and explain the plans in our AQL guide.