本国际标准规定了离散项目变量检验的顺序抽样计划和程序。 这些计划根据生产者的风险点和消费者的风险点进行索引。因此，它们不仅适用于验收抽样的目的，而且适用于检验比例的简单统计假设的更一般的目的。 本国际标准的目的是为检验结果的顺序评估提供程序，该程序可用于诱导供应商供应具有高验收概率的质量批次。同时，消费者受到接受大量（或过程）质量差的概率的规定上限的保护。 本国际标准主要设计用于以下条件:a)检验程序将应用于所有由一个生产商使用一种生产工艺供应的连续系列离散产品批次。在这种情况下，特定批次的采样等同于过程的采样。如果有不同的生产者或生产过程，本国际标准应分别适用于每一个； b)其中仅考虑这些产品的单个质量特性x，其必须在连续尺度上可测量； c)其中测量误差可忽略不计(即标准偏差不超过工艺标准偏差的10%)； d)其中生产稳定(在统计控制下)并且质量特性x具有已知的标准偏差，并且根据正态分布或接近正态分布的近似分布；注意—本国际标准中的程序不适用于先前筛选过不合格项目的批次。 e)其中合同或标准定义了规格上限U、规格下限L或两者；当且仅当一个项目的测量质量特性x满足以下不等式中的适当一个时，该项目才合格: x≤U（即不违反质量标准上限）； x≥L（即不违反质量标准下限）； 并且（即，既不违反质量标准的上限也不违反质量标准的下限。） 不等式1）和2）被称为具有“单规格极限”的情况，3）是具有“双规格极限”的情况。 在本国际标准中，假定当两个质量标准限值适用时，符合两个质量标准限值对产品的完整性同等重要，或者对两个质量标准分别考虑极限。在第一种情况下，将产品的合并百分比控制在两个质量标准限度之外是合适的。这被称为组合控制。在第二种情况下，单独控制超过每个限值的不符合，并且这被称为单独控制。

This International Standard specifies sequential sampling plans and procedures for inspection by variables of discrete items. The plans are indexed in terms of producer's risk point and the consumer's risk point. Therefore, they are suitable not only for the purposes of acceptance sampling, but for the more general purpose of the testing of simple statistical hypotheses for proportions. The purpose of this International Standard is to provide procedures for the sequential assessment of inspection results that may be used to induce the supplier to supply lots of a quality having a high probability of acceptance. At the same time, the consumer is protected by a prescribed upper limit to the probability of accepting a lot (or process) of poor quality. This International Standard is primarily designed for use under the following conditions: a) where the inspection procedure is to be applied to a continuing series of lots of discrete products all supplied by one producer using one production process. In such a case, sampling of particular lots is equivalent to the sampling of the process. If there are different producers or production processes, this International Standard shall be applied to each one separately; b) where only a single quality characteristic x of these products is taken into consideration, which must be measurable on a continuous scale; c) where the measurement error is negligible (i.e. with a standard deviation no more than 10 % of the process standard deviation); d) where production is stable (under statistical control) and the quality characteristic x has a known standard deviation, and is distributed according to a normal distribution or a close approximation to the normal distribution; CAUTION — The procedures in this International Standard are not suitable for application to lots that have been screened previously for nonconforming items. e) where a contract or standard defines an upper specification limit U, a lower specification limit L, or both; an item is qualified as conforming if and only if its measured quality characteristic, x, satisfies the appropriate one of the following inequalities:

1. x ≤ U (i.e. the upper specification limit is not violated);
2. x ≥ L (i.e. the lower specification limit is not violated);
3. and (i.e. neither the upper nor the lower specification limit is violated.)

Inequalities 1) and 2) are called cases with a "single specification limit", and 3) is the case with "double specification limits". In this International Standard, it is assumed that, where double specification limits apply, conformance to both specification limits is either equally important to the integrity of the product or is considered separately for both specification limits. In the first case, it is appropriate to control the combined percentage of product outside the two specification limits. This is referred to as combined control. In the second case, nonconformity beyond each of the limits is controlled separately, and this is referred to as separate control.