TS ISO 3951-1

TS ISO 3951-1 addresses an acceptance sampling system of single sampling plans indexed by acceptance quality limit (AQL) for inspection by variables, focused on one quality characteristic. In this approach, lot acceptability is assessed from measured data taken from a random sample, with the aim of estimating the proportion of nonconforming items in the lot rather than relying only on a pass/fail count.

How variables-based acceptance sampling works

Inspection by variables uses numerical measurements, so it can incorporate more information than attribute inspection, which classifies items simply as conforming or nonconforming. Because the data are measured, the method can use both location and spread of the sample results to judge the lot. In acceptance sampling practice, the AQL represents the quality level used as a reference point when designing or selecting a plan; here the standard is limited to single plans for a single quality characteristic and a single AQL.

What this standard sets out

The standard specifies the acceptance sampling system for lot-by-lot inspection based on random samples drawn from the lot. Its purpose is to estimate the percentage of nonconforming items in the process or lot and use that estimate to determine acceptability. In broader technical terms, this places measured-product quality control within a statistical framework where the sample result stands in for the lot as a whole. The product listing reflects the standard’s system definition; it does not imply every practical detail of implementation is contained here.

• Designed for one quality characteristic.
• Indexed by a single AQL.
• Applies to lot-by-lot inspection.
• Uses random samples and measured values.
• Acceptance is based on estimating the percentage of nonconforming items.