Acceptable Quality Level (AQL)
The acceptable quality level (AQL) is based on the standard MIL-STD-105E / ISO 2859-1. It represents the maximum percent of defects acceptable in a production run. (or the maximum number of defects per hundred units). This definition has since been changed to Acceptable Quality.
Acceptance Quality Limit
AQL is now Acceptance Quality Limit in most standards. It defines the quality level that is the worst tolerable process average when a continuing series of lots is submitted for acceptance sampling.
It is the limit of defects that the customer is prepared to accept. For example - I want no more than 2.5% of defective product units in the total order. In this case, the AQL is 2.5%.
The following note on the meaning of AQL was introduced with the ANSI/ASQ Z1.4-2003 . revision: The concept of AQL only applies when an acceptance sampling scheme with rules for switching between normal, tightened and reduced inspection and discontinuance of sampling inspection are used. These rules are designed to encourage suppliers to have process averages consistently better than the AQL. If suppliers fail to do so, there is a high probability of being switched from normal inspection to tightened inspection where lot acceptance becomes more difficult.
An approval sample, also called a ‘golden sample,’ ‘pre-production sample’ or ‘PP-sample,' is usually sent by the buyer to the third-party inspection company and manufacturer. It is the reference product that will be compared to the production samples. The production and approval samples should be very similar. An inspection report will point out the differences.
Read more about the role of the approval sample during an inspection.
Consumer quality standards
Container Loading Inspection (CLI)
- an inspection of the container before the loading (container condition)
- an inspection of your products (product checks according to your P/O: quantity, appearance, and general quality)
- an inspection of the loading process (conditions of cartons, filling-up level, etc.)
Continuous Sampling Plan
Cost of Poor Quality
Cost of Quality
Defects and Defectives
Defects per Hundred Units
Double Sampling Plan
Drawing of Samples
During Production Inspection (DPI)
Expression of Nonconformance
First-Articles Inspection (FAI)
In-process Quality Control (IPQC)
Inspection by Attribute
- The difference between the general and special inspection level of the AQL table.
- How to choose the right AQL inspection level.
Letter of Credit
Lot or Batch
A major defect is one, that is likely to result in failure, or to materially reduce the usability of the unit of product for its intended purpose. It is less serious than a critical defect. A major defective is a unit of product that contains one or more major defects. You can provide your own list of Major Defects to be inspected. AQF’s default AQL for major defects is 2.5.
Online Quality Management system/technology/software
Pre-Shipment Inspection (PSI)