本文件按属性规定了两阶段（双重）抽样计划，用于检查离散单元目标群体中的一部分不合格项目，特别是: a） 许多产品项目中不合格项目的比例； b） 内部控制系统（ICS）不合格功能实例的比例； c） 错报在会计分录或记账记录总体中的比例； d） 接受验收测试的实体的不合格测试特征的比例，例如在产品和过程审核中。 如果检验成本高，或者第二个样品的可能要求造成的延迟和不确定性无关紧要，则该计划优于单一抽样计划。计划、表格和数字的统计理论见附件A到K。

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.