The Average Quantity System (AQS)
The Average Quantity System (AQS) is how Trading Standards Officers assess whether pre-packaged goods comply with the Weights and Measures Act.
About the Average Quantity System (AQS)
The Average Quantity System (AQS) is described in the Weights and Measures Regulations. It provides a sampling plan and criteria for Trading Standards Officers to use to check that a defined batch/lot of prepackaged goods meets the requirements of the AQS, by testing a statistical sample of the batch/lot.
The AQS applies a tolerance to the sample known as a ‘tolerable deficiency’. This is stated in Regulation 84C and is dependent on the actual net contents of the package under test. Packages are permitted to be equal to, or greater than, the stated quantity minus the tolerable deficiency specified in the regulations.
Weights and Measures Regulations 1999 — Regulation 84C, Non-standard package(external link)
The requirements of the AQS
To comply with the AQS, a sample of packages taken from a batch must meet these requirements:
- The average quantity of a sample must not be less than the stated quantity marked on the packages.
- A small number of packages may contain less than the quantity stated on the package. The deficiency can be more than the tolerable deficiency (T1), but not more than twice the tolerable deficiency (T2). These are referred to as ‘non-standard packages’.
- No individual package is allowed a deficiency greater than twice the allowed tolerable deficiency. These packages are referred to as ‘inadequate – packages’ (T2).
Alert
It is important that these definitions are read in conjunction with the three requirements of AQS.
Your sampling plans
The AQS model in the Regulations is not a statistical model for packers to pack to. If you use these criteria in your production processes you run the risk of packing short weight, measure or number products.
To ensure your packaged goods meet the quantity statement shown on the individual package, you must either:
- measure the contents of each package, or
- develop your own statistical model (sampling plans) designed to ensure that any sample taken from the lot will meet the AQS requirements described above.
Packers and importers’ sampling plans must be sufficiently rigorous to provide confidence that the requirements of the AQS have been satisfied.
If you need help understanding the Average Quantity System, Trading Standards Officers are available to come and talk to you, and can demonstrate the inspection procedure they would use to determine compliance.