1 Scope
This document specifies two-stage (double) sampling plans by attributes for inspection
for a proportion of nonconforming items in a target population of discrete units, in particular:
a) the proportion of nonconforming items in a lot of product items;
b) the proportion of nonconforming function instances of an internal control system (ICS);
c) the proportion of misstatements in a population of accounting entries or booking records;
d) the proportion of nonconforming test characteristics of an entity subject to an acceptance
test, e.g. in product and process audits.
The plans are preferable to single sampling plans where the cost of inspection is
high or where the delay and uncertainty caused by the possible requirement for second
samples is inconsequential. The statistical theory underlying the plans, tables and figures
are provided in Annexes A through K.
BS ISO 28596:2022 history
2022BS ISO 28596:2022 Sampling procedures for inspection by attributes. Two-stage sampling plans for auditing and for inspection under prior information