ISO 8423:2008 不合格品率的计量序贯抽样检验程序（标准差已知）

标准编号：ISO 8423:2008

中文名称：不合格品率的计量序贯抽样检验程序（标准差已知）

英文名称：Sequential sampling plans for inspection by variables for percent nonconforming (known standard deviation)

发布日期：2008-09

标准范围

ISO 8423:2008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，也适用于更一般的测试比例的简单统计假设。ISO 8423:2008的目的是提供检验结果的顺序评估程序，该程序可用于诱导供应商提供具有高验收概率的质量批次。同时，消费者接受大量劣质产品（或工艺）的概率有一个规定的上限。ISO 8423:2008主要设计用于以下条件:检验程序适用于连续系列的离散产品，所有产品均由一个生产商使用一种生产工艺提供；仅考虑这些产品的单一质量特征，必须在连续范围内进行测量；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%）；生产稳定（在统计控制下），且质量特性具有已知的标准偏差，且根据正态分布或正态分布的近似分布进行分布；合同或标准规定了规格上限、规格下限或两者。假设在双规格限制适用的情况下，符合两个规格限制对产品的完整性同等重要，或者对两个规格限制单独考虑。ISO 8423中的程序:2008不适用于之前筛选不合格品的批次。

ISO 8423:2008 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 ISO 8423:2008 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.ISO 8423:2008 is primarily designed for use under the following conditions: 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; where only a single quality characteristic of these products is taken into consideration, which must be measurable on a continuous scale; where the measurement error is negligible (i.e. with a standard deviation no more than 10 % of the process standard deviation); where production is stable (under statistical control) and the quality characteristic has a known standard deviation, and is distributed according to a normal distribution or a close approximation to the normal distribution; where a contract or standard defines an upper specification limit, a lower specification limit, or both. 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.The procedures in ISO 8423:2008 are not suitable for application to lots that have been screened previously for nonconforming items.

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