1.1 本规程主要是指导ASTM技术委员会和其他机构使用平均出厂质量限值、AOQL和批次公差缺陷百分比、LTPD的原则声明，以确定产品批次的可接受性。 1.2 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 4.1 两种通用表格类型( 注1 )一个基于批次公差LTPD的概念，另一个基于AOQL。不同类型最适合的广泛条件如下所示。 4.1.1 对于每种类型，提供了单次采样和双次采样的表格。每一个单独的表格都构成了一个解决方案的集合，以尽量减少总体检查量。因为表中的每一行都涵盖了一系列批次大小，所以LTPD表中的AOQL值和AOQL表中的LTPD值通常是保守的。 注1: 中的表 附件A1- 附件A4 经约翰·R·威利父子公司许可，部分文本得以复制。该文将提供更广泛的表格和方法讨论。 4.2 基于批次质量保护（LTPD）的抽样表（ 附件A1 和 附件A2 )可能最适合于兴趣分别集中在每个批次上的情况，例如，从装运或服务的角度来看，单个批次倾向于保留其身份。 这些表格在最终消费者或采购代理对或多或少间歇性购买的批次或货物进行检查时特别有用。 4.3 基于平均质量保护（AOQL）的抽样表（ 附件A3 和 附件A4 )特别适用于关注检验后产品的平均质量，而不是每批产品的质量，因此，如果需要，检验旨在作为缺陷件的部分筛选。后一种观点被发现特别有用，例如，在消费者对持续大量购买产品的检查中，以及在零件的制造过程中，检查批次往往会因合并在一个公共仓库中而失去其身份，根据需要从该仓库中提取数量。 4.4 基于平均质量保护（AOQL）的计划考虑了整个检验程序在多大程度上筛选出提交给检验员的产品中的缺陷。通过消除样品中发现的缺陷，对样品接受的批次进行部分筛选。未通过样品验收的批次将完全清除缺陷。显然，这需要进行无损检测。总的结果是，当产品离开检查员时，产品的平均缺陷百分比，称为 平均输出质量 ，这取决于来料的缺陷百分比水平和筛选出的总缺陷比例。 4.5 给定替换100的特定问题 % 通过抽样检查进行筛选检查，第一步是确定所需的保护类型，为该类型的保护选择所需的缺陷批次公差百分比（LTPD）或AOQL值，并在单次和双次抽样之间进行选择。 这将导致选择一个附加表。第二步是确定产品质量是否足够好，以保证引入抽样。当然，只有在提交的产品中的缺陷百分比达到所选抽样计划的验收标准时，才能实现抽样经济。因此，应首先对过去的检查结果进行统计分析，以确定所考虑的特征或特征组的缺陷百分比的现有水平和波动。这提供了有关控制程度的信息，以及在现有条件下预计的缺陷百分比的通常水平。根据此信息和其他信息确定 过程平均值 如果要引入抽样，则应用所选抽样表时应使用的缺陷百分比。

1.1 This practice is primarily a statement of principals for the guidance of ASTM technical committees and others in the use of average outgoing quality limit, AOQL, and lot tolerance percent defective, LTPD, sampling plans for determining acceptable of lots of product. 1.2 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 Two general types of tables ( Note 1 ) are given, one based on the concept of lot tolerance, LTPD, and the other on AOQL. The broad conditions under which the different types have been found best adapted are indicated below. 4.1.1 For each of the types, tables are provided both for single sampling and for double sampling. Each of the individual tables constitutes a collection of solutions to the problem of minimizing the over-all amount of inspection. Because each line in the tables covers a range of lot sizes, the AOQL values in the LTPD tables and the LTPD values in the AOQL tables are often conservative. Note 1: Tables in Annex A1 – Annex A4 and parts of the text are reproduced by permission of John R. Wiley and Sons. More extensive tables and discussion of the methods will be found in that text. 4.2 The sampling tables based on lot quality protection (LTPD) (the tables in Annex A1 and Annex A2 ) are perhaps best adapted to conditions where interest centers on each lot separately, for example, where the individual lot tends to retain its identity either from a shipment or a service standpoint. These tables have been found particularly useful in inspections made by the ultimate consumer or a purchasing agent for lots or shipments purchased more or less intermittently. 4.3 The sampling tables based on average quality protection (AOQL) (the tables in Annex A3 and Annex A4 ) are especially adapted for use where interest centers on the average quality of product after inspection rather than on the quality of each individual lot and where inspection is, therefore, intended to serve, if necessary, as a partial screen for defective pieces. The latter point of view has been found particularly helpful, for example, in consumer inspections of continuing purchases of large quantities of a product and in manufacturing process inspections of parts where the inspection lots tend to lose their identity by merger in a common storeroom from which quantities are withdrawn on order as needed. 4.4 The plans based on average quality protection (AOQL) consider the degree to which the entire inspection procedure screens out defectives in the product submitted to the inspector. Lots accepted by sample undergo a partial screening through the elimination of defectives found in samples. Lots that fail to be accepted by sample are completely cleared of defectives. Obviously, this requires a nondestructive test. The over-all result is some average percent defective in the product as it leaves the inspector, termed the average outgoing quality , which depends on the level of percent defective for incoming product and the proportion of total defectives that are screened out. 4.5 Given a specific problem of replacing a 100 % screening inspection by a sampling inspection, the first step is to decide on the type of protection desired, to select the desired limit of percent defective lot tolerance (LTPD) or AOQL value for that type of protection, and to choose between single and double sampling. This results in the selection of one of the appended tables. The second step is to determine whether the quality of product is good enough to warrant the introduction of sampling. The economies of sampling will be realized, of course, only insofar as the percent defective in submitted product is such that the acceptance criteria of the selected sampling plan will be met. A statistical analysis of past inspection results should first be made, therefore, in order to determine existing levels and fluctuations in the percent defective for the characteristic or the group of characteristics under consideration. This provides information with respect to the degree of control as well as the usual level of percent defective to be expected under existing conditions. Determine a value from this and other information for the process average percent defective that should be used in applying the selected sampling table, if sampling is to be introduced.