TS ISO 8422

TS ISO 8422 is a standard on sequential sampling plans for inspection by attributes. In this type of acceptance inspection, the decision about a lot or process is built up as individual sample results are obtained, rather than waiting for a fixed full sample to be completed. The standard addresses the plans and operating procedures used for this form of inspection.

What sequential attribute inspection means

Sequential sampling differs from single-sampling or double-sampling inspection because each observed unit can contribute to an earlier accept/reject decision. In general technical terms, it is useful when inspection is costly, time-sensitive, or when reducing unnecessary examination is important. Inspection by attributes means the item is judged in categorical terms, such as conforming/nonconforming or pass/fail, rather than by a continuous measurement.

The scope covered by this standard

The scope of TS ISO 8422 is the sequential sampling plans and procedures for inspection by attributes of discrete items. Based on the information provided here, the standard is about the statistical structure of the plan and its operating logic, not about specific numerical acceptance limits or detailed test steps. For consistent terminology, related statistical definitions are aligned with references such as TS ISO 3534-1.

• Attribute inspection evaluates items by category, not by a measured scale.
• Sequential plans allow decisions to be made as results accumulate.
• The method links acceptance or rejection to statistical decision rules.
• It is designed around the ordered examination of sample results.