SANS 2859-3-2008 Sampling procedures for inspection by attributes Part 3 Skip-lot sampling procedures《属性检验用抽样程序 第3部分 箕斗式取样程序》.pdf

1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA

2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any

3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-21181-3 SANS 2859-3:2008 Edition 1 ISO 2859-3:2005 Edition 2SOUTH AFRICAN NATIONAL STANDARD Sampling procedures for inspection by attribut

4、es Part 3: Skip-lot sampling procedures This national standard is the identical implementation of ISO 2859-3:2005 and is adopted with the permission of the International Organization for Standardization. Published by Standards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001

5、tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa This standard may only be used and printed by approved subscription and freemailing clients of the SABS.SANS 2859-3:2008 Edition 1 ISO 2859-3:2005 Edition 2 Table of changes Change No. Date Scope N

6、ational foreword This South African standard was approved by National Committee StanSA TC 169, Applications of statistical methods, in accordance with procedures of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This SANS document was published in April 2008. This stand

7、ard may only be used and printed by approved subscription and freemailing clients of the SABS. Reference number ISO 2859-3:2005(E) ISO 2005INTERNATIONAL STANDARD ISO 2859-3 Second edition 2005-05-01 Sampling procedures for inspection by attributes Part 3: Skip-lot sampling procedures Rgles dchantill

8、onnage pour les contrles par attributs Partie 3: Procdures dchantillonnage successif partiel SANS 2859-3:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 2859-3:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In acco

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13、Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2005 All rights reservedSANS 2859-3:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 2859-3:2005(E) ISO 2005 A

14、ll rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references . 1 3 Terms, definitions and symbols 1 3.1 Terms and definitions. 1 3.2 Symbols and abbreviated terms 3 4 General requirements . 3 5 Supplier and product qualification 4 5.1 Supplier qualification 4 5.2 Product qualific

15、ation 5 5.3 Qualification score 6 5.4 Example for product qualification. 8 6 Skip-lot sampling procedures . 9 6.1 General. 9 6.2 Initial inspection frequency and its determination 11 6.3 Inspection frequency and shifting 11 6.4 Sampling plans, lot selection and inspection procedures (States 2 and 3)

16、 . 14 6.5 Skip-lot interruption 15 6.6 Requalification 16 6.7 Product disqualification . 16 6.8 Supplier disqualification and suspension17 7 Supplier responsibilities 17 8 Inspection agency and responsible authority responsibilities 18 8.1 General. 18 8.2 Responsibilities on supplier qualification 1

17、9 8.3 Other responsibilities . 19 9 Compatibility with ISO 2859-1 20 9.1 Limitations . 20 9.2 Relation to reduced inspection . 20 10 Additional information 21 10.1 Design basis 21 10.2 Statistical characteristics of the skip-lot procedures . 21 Annex A (normative) Optional requirements to be agreed

18、prior to product qualification 23 Annex B (normative) Procedures for random selection at specified inspection frequency 25 Annex C (informative) Factors used in deciding between skip-lot inspection and reduced inspection 27 Bibliography . 29 SANS 2859-3:2008This standard may only be used and printed

19、 by approved subscription and freemailing clients of the SABS.ISO 2859-3:2005(E) iv ISO 2005 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards

20、is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take pa

21、rt in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to

22、prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility th

23、at some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 2859-3 was prepared by Technical Committee ISO/TC 69, Applications of statistical methods, Subcommittee SC 5, Acceptance sampling. This s

24、econd edition cancels and replaces the first edition (ISO 2859-3:1991), which has been technically revised. ISO 2859 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-b

25、y-lot inspection Part 2: Sampling plans indexed by limiting quality (LQ) for isolated lot inspection Part 3: Skip-lot sampling procedures Part 4: Procedures for assessment of declared quality levels Part 5: System of sequential sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot

26、inspection. Part 10: Overview of the ISO 2859 attribute sampling systems SANS 2859-3:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.INTERNATIONAL STANDARD ISO 2859-3:2005(E) ISO 2005 All rights reserved 1Sampling procedures for inspection

27、by attributes Part 3: Skip-lot sampling procedures 1 Scope This part of ISO 2859 specifies generic skip-lot sampling procedures for acceptance inspection by attributes. The purpose of these procedures is to provide a way of reducing the inspection effort on products of high quality submitted by a su

28、pplier who has a satisfactory quality assurance system and effective quality controls. The reduction in inspection effort is achieved by determining at random, with a specified probability, whether a lot presented for inspection will be accepted without inspection. This procedure extends the princip

29、le of the random selection of sample items already applied in ISO 2859-1 to the random selection of lots. The skip-lot sampling procedures specified in this part of ISO 2859 are applicable to, but not limited to, inspection of a) end items, such as complete products or sub-assemblies, b) components

30、and raw materials, and c) materials in process. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any

31、 amendments) applies. ISO 2859-1:1999, Sampling procedures for inspection by attributes Part 1:Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection ISO 3534-1, Statistics Vocabulary and symbols Part 1: Probability and general statistical terms ISO 3534-2, Statistics V

32、ocabulary and symbols Part 2: Applied statistics 3 Terms, definitions and symbols 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 2859-1, ISO 3534-1, ISO 3534-2 and the following apply. For ease of reference, some terms are quoted from these standa

33、rds. 3.1.1 continuous production production that is at a steady rate NOTE Production is considered continuous if the production has been continued for a specified production period at a specified production frequency (see 5.2.1). Continuous production is considered a stabilizing factor of the manufa

34、cturing or assembly processes. SANS 2859-3:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 2859-3:2005(E) 2 ISO 2005 All rights reserved3.1.2 disqualification failure to qualify for skip-lot sampling inspection (3.1.11) 3.1.3 inspection

35、 agency independent third party with the responsibility for lot inspection and qualification assessment 3.1.4 inspection frequency probability that a lot is inspected NOTE Inspection frequencies specified in this part of ISO 2859 are 1/2,1/3,1/4 and 1/5. 3.1.5 interruption cessation of skip-lot samp

36、ling inspection (3.1.11), ending with a return either to skip-lot sampling inspection or to lot-by-lot inspection 3.1.6 lot-by-lot inspection inspection of products submitted in a series of lots NOTE 1 In this part of ISO 2859, a sample (or samples) is (are) drawn from each lot and inspected using a

37、cceptance sampling procedures by attributes given in ISO 2859-1. NOTE 2 In this part of ISO 2859, lot-by-lot inspection is used both in State 1 (qualification period) and State 3 (skip-lot interruption state) (see 5.1). 3.1.7 product qualification assessment of the product to determine its suitabili

38、ty for skip-lot sampling inspection (3.1.11) 3.1.8 qualification score running total derived according to given rules from the immediately preceding quality history, and used in making decisions regarding qualification, changes in inspection frequency (3.1.4), interruption (3.1.5), disqualification

39、(3.1.2) and requalification (3.1.9) 3.1.9 requalification qualification for a resumption of skip-lot sampling inspection (3.1.11) 3.1.10 responsible authority person or group of people who has responsibility and authority to manage inspection systems appropriately NOTE In this part of ISO 2859, the

40、responsible authority has responsibility and authority to assess and verify supplier qualification, decide various criteria and judge switch inspection stages. 3.1.11 skip-lot sampling inspection sampling inspection procedure in which some lots in a series are accepted without inspection when the sa

41、mpling results for a stated number of immediately preceding lots meet stated criteria NOTE The lots to be inspected are chosen randomly in accordance with a stated (skip-lot) inspection frequency. An inspection frequency of 1 in 2, for example, means that the long run average proportion of lots insp

42、ected is 1/2. SANS 2859-3:2008This standard may only be used and printed by approved subscription and freemailing clients of the SABS.ISO 2859-3:2005(E) ISO 2005 All rights reserved 33.1.12 supplier qualification assessment of the suppliers competence to implement skip-lot sampling inspection (3.1.1

43、1) 3.2 Symbols and abbreviated terms The symbols and abbreviated terms used in this document are as follows: Ac acceptance number; Ac 0acceptance number for the corresponding single sampling plan; Ac 1first acceptance number (for the double or multiple sampling plan); Ac 2second acceptance number (f

44、or the double or multiple sampling plan); d number of nonconforming items or nonconformities in the sample; k number of lots used for inspection frequency (the inspection frequency is 1 in k; i.e. 1/k); n sample size. 4 General requirements 4.1 Skip-lot inspection may only be used when both the supp

45、lier and the product are qualified. The requirements for qualification are specified in Clause 5. NOTE The skip-lot sampling procedures specified in this part of ISO 2859 should be distinguished from Dodges skip-lot sampling plans. See 1, 2 and 3 in the Bibliography. 4.2 This part of ISO 2859 is int

46、ended to supplement the ISO 2859-1 sampling system, and may be used together with ISO 2859-1. Unless otherwise specified in this part of ISO 2859, the provisions of ISO 2859-1 shall apply. ISO 2859-10 provides useful information concerning the use of the standards in the ISO 2859 series. 4.3 The ski

47、p-lot sampling procedures specified in this part of ISO 2859 are intended only for a continuing series of lots and shall not be used for isolated lots. All lots in the series are expected to be of a similar quality and there should be reason to believe that lots not inspected are of the same quality

48、 as the ones inspected. 4.4 Skip-lot sampling may be used instead of reduced inspection if it is more cost effective to do so (see 9.2 and Annex C), but its application and switching rules are different from those of reduced inspection in ISO 2859-1. 4.5 There are some limitations to the use of skip

49、-lot sampling procedures (see 9.1). 4.6 When different acceptance quality limit (AQL) values are specified for two or more classes of nonconforming items or nonconformities, special care should be taken to ensure correct application of the standard (see 5.2.2 to 6.6 and 10.2). 4.7 Inspection may take place at the suppliers or purchasers locations, or at an interface between operations of a production process. 4.8 As every product has its own environment and characteristics, options are provided so that the suppl