According to “Sampling by Attributes Using the ANSI/ASQ Z1.4-2008 Standard,” you find information about inspection levels and rules, sampling plan types, inspection procedures, how to apply a sampling plan to check for packaging defects and what sampling statistics mean.
ANSI/ASQ Z1.4 2008 describes industry standards with three levels of plans to sample products and document their conformance to acceptance criteria. The standard seeks to improve accuracy of sampling procedures by helping manufacturers avoid mistakes in choosing correct sampling sizes, acceptance criteria and other sampling issues.
Sampling products is important and even mandatory in many sectors of the supply chain. For instance, when a manufacturer inspects products for shipping, he makes a decision about which packages conform to his standards. Shippers accept or reject products based on attribute sampling, as do vendors and end-consumers. ANSI/ASQ Z1.4 2008 provides detailed information about choosing the sampling plan best suited to a particular packaging standard or shipment.
Important information for sampling purposes includes lot size, inspection level and sampling methodology as well as historical data on how often an organization accepts or rejects lots and their selection criteria. Once this information is known, manufacturers and shippers have a clearer idea of how big a sample to use. For example, good acceptance history, which means good adherence to packaging standards, may allow the use of smaller samples, while a poor track record may increase sampling size or lead manufacturers to discontinue some packaging practices.