GB/T / ISO :1999

Transcription

1 Translated English of Chinese Standard: GB/T GB NATIONAL STANDARD OF THE PEOPLE S REPUBLIC OF CHINA ICS A 41 GB/T / ISO :1999 Replacing GB/T Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection 计数抽样检验程序第 1 部分 : 按接收质量限 (AQL) 检索的逐批检验抽样计划 (ISO :1999, IDT) Issued on: November 5, 2012 Implemented on: February 15, 2013 Issued by: General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China; Standardization Administration of the People's Republic of China. Page 1 of 138

2 Table of Contents Foreword Scope Normative references Terms, definitions and symbols Expression of nonconformity Acceptance quality limit (AQL) Submission of product for sampling Acceptance and non-acceptance Drawing of samples Normal, tightened and reduced inspection Sampling plans Determination of acceptability Further information Fractional acceptance number plans for single sampling (optional) Annex A (informative) Example for non-constant sampling plan (Level II, AQL = 1.0 (%)) Bibliography Page 2 of 138

3 Foreword GB/T 2828 consists of the following parts, under the general title Sampling procedures for inspection by attributes: - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection (ISO :1999, IDT) - Part 2: Sampling plans indexed by limiting quality (LQ) for isolated lot inspection (ISO :1985, NEQ) - Part 3: Skip-lot sampling procedures (ISO :2005, IDT) - Part 4: Procedures for assessment of declared quality levels (ISO :2002, MOD) - Part 5: System of sequential sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection (ISO :2005, IDT) - Part 10: Introduction to the GB/T 2828 attribute sampling system (ISO :2006, MOD) - Part 11: Procedures for assessment of declared quality levels for small population This Part is Part 1 of GB/T This Part is drafted according to the rules given in GB/T This Part replaces GB/T Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection. Compared with GB/T , main changes of technical contents are as follows: - Terms and definitions, symbols are modified according to GB/T For example, sampling characteristic curve is changed to operating characteristic curve ; the description to defect is changed from the term defect is appropriate for use when a quality characteristic of a product or service is evaluated in terms of conformance to specifications to the term defect is appropriate for use when a quality characteristic of a product or service is evaluated in terms of usage as contrasted to conformance to specifications ; - In Table 9, average sample size curves for single, double and multiple sampling, add the curve of Ac = 4; - Parts of textual descriptions have been modified. Page 3 of 138

4 This Part equivalently adopts the International Standard ISO :1999 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection and the Technical Corrigendum of ISO :1999 published on March 1, At the same time this Part retains the following corrections to ISO :1999 made in GB/T :2003: - On the curve of Ac = 12 in Table 9, delete the arrow; - On the curve of Ac = 7 in Table 9, move the arrow from 3 to On the curves of Ac = 27, Ac = 30, Ac = 41 and Ac = 44, change the axis to n nonconformities per 100 items/100. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing organizations of this document shall not be held responsible for identifying any or all such patent rights. This Part is proposed by China National Institute of Standardization. This Part shall be under the jurisdiction of National Technical Committee on Statistical Methods and Application of Standardization Administration of China (SAC/TC 21). Drafting organizations of this Part: China National Institute of Standardization, China PLA Ordnance Engineering College, Academy of Mathematics and Systems Science of Chinese Academy of Sciences, Xia men Hua Ce Testing Technology Co., Ltd. Main drafters of this Part: Yu Zhenfan, Zhang Yuzhu, Ding Wenxing, Xiao Hui, Zhang Fan, Feng Shiyong, Ma Yilin, Liu Wen and Wan Feng. The previous edition of the standards replaced by this Part are as follows: - GB , GB/T and GB/T Page 4 of 138

5 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection 1 Scope 1.1 This Part specifies an acceptance sampling system for inspection by attributes. It is indexed in terms of the acceptance quality limit (AQL). The purpose of this Part is to induce a supplier through the economic and psychological pressure of lot non-acceptance to maintain a process average at least as good as the specified acceptance quality limit, while at the same time providing an upper limit for the risk to the consumer of accepting the occasional poor lot. Sampling schemes designated in this Part are applicable (but not limited) to inspection of - end items, - components and raw materials, - operations, - materials in process, - supplies in storage, - maintenance operations, - data or records, and - administrative procedures. 1.2 These schemes are intended primarily to be used for a continuing series of lots, that is, a series long enough to allow the switching rules (see 9.3) to be applied. These rules provide: a) a protection to the consumer (by means of a switch to tightened inspection or discontinuation of sampling inspection) should a deterioration in quality be detected; Page 5 of 138

6 Bibliography [1] GB/T Sampling procedures for inspection by attributes - Part 10: Introduction to the GB/T 2828 attribute sampling system. [2] GB/T Sampling procedures for inspection by attributes - Part 2: Sampling plans indexed by limiting quality (LQ) for isolated lot inspection. [3] GB/T Sampling procedures for inspection by attributes - Part 11: Procedures for assessment of declared quality levels for small population. [4] GB/T Sampling procedures for inspection by variables - Part 1: Specification for single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a single quality characteristic and a single AQL. [5] GB/T Quality management and quality assurance - Vocabulary. END Page 138 of 138