1、Americ An nAtionAl St And Ard AMERICAN SOCIETY FOR QUALITY 600 N. PLANKINTON AVENUE MILWAUKEE, WI 53203-2914 ASQ/ANSI S1 2012 An attribute skip-lot sampling programiii ASQ/ANSI S1 2012 Americ An nAtionAl S t And Ard An attribute skip-lot sampling program Approved as an American National Standard by:
2、 American Society for Quality Standards Committee May 18, 2012 An attribute skip-lot sampling program provides procedures for reducing the inspection effort on products that satisfy supplier and production qualification criteria. The standard is to be used only in conjunction with the latest version
3、 of ANSI/ASQ Z1 .4. American National Standards: An American National Standard implies a consensus of those substantially concerned with its scope and provisions. An American National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an A
4、merican National Standard does not in any respect preclude anyone, whether he or she has approved the standard or not, from manufacturing, purchasing, or using products, processes, or procedures not conforming to the standard. American National Standards are subject to periodic review and users are
5、cautioned to obtain the latest information. Caution Notice: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from t
6、he date of publication. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute.ASQ/ANSI S1 2012 iv 2012 by ASQ All rights reserved. No part of this publication may be reproduced in any form, in an ele
7、ctronic retrieval system or otherwise, without the prior written permission of the publisher. Copyright Protection Notice for the ASQ/ANSI SI 2012 Standard. This standard is subject to copyright claims of ANSI and ASQ. Not for resale. No part of this publication may be reproduced in any form, includ
8、ing an electronic retrieval system, without the prior written permission of ASQ. All requests pertaining to the ASQ/ANSI SI 2012 Standard should be submitted to ASQ. note: As used in this document, the term “International Standard” refers to the American National Standard adoption of this and other
9、International Standards. ASQ will consider requests for change and information on the submittal of such requests regarding this Standard. All requests should be in writing to the attention of the Standards administrator at the address below. ASQ mission: The American Society for Quality advances ind
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13、GHT PROTECTED DOCUMENTv ASQ/ANSI S1 2012 Also available from ASQ Quality Press: ASQ/ANSI S3-2012: An attribute chain sampling program ANSI/ASQ Z1 .4-2008: Sampling Procedures and T ables for Inspection by Attributes ANSI/ASQ Z1 .9-2008: Sampling Procedures and T ables for Inspection by Variables for
14、 Percent Nonconforming ANSI/ISO/ASQ 2859-1:1999: Sampling procedures for inspection by attributes Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection ANSI/ISO/ASQ 2859-4:2002: Sampling procedures for inspection by attributes Part 4: Procedures for assessment
15、of declared quality levels ANSI/ISO/ASQ Q9001-2008: Quality management systems Requirements The Handbook of Applied Acceptance Sampling: Plans, Procedures, and Principles Kenneth S. Stephens Zero Acceptance Number Sampling Plans, Fifth Edition Nicholas L. Squeglia The Certified Quality Engineer Hand
16、book, Third Edition Connie M. Borror, editor The Desk Reference of Statistical Quality Methods, Second Edition Mark L. Crossley The Quality Toolbox, Second Edition Nancy R. T ague The Certified Six Sigma Green Belt Handbook Roderick A. Munro, Matthew J. Maio, Mohamed B. Nawaz, Govindarajan Ramu, and
17、 Daniel J. Zrymiak The Certified Manager of Quality / Organizational Excellence Handbook: Third Edition Russell T . Westcott, editor Root Cause Analysis: Simplified Tools and Techniques, Second Edition Bjrn Andersen and T om Fagerhaug The Certified Six Sigma Black Belt Handbook, Second Edition T.M.
18、Kubiak and Donald W. Benbow To request a complimentary catalog of ASQ Quality Press publications, call 800-248-1946, or visit our Web site at http:/www.asq.org/quality-press.(This page intentionally left blank.)contents Foreword. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .viii 1.0 introduction 1 1 .1 Scope and purpose . 1 1 .2 Field of application 1 2.0 r eferences 2 3.0 t erms and definitions . 3 3.1 Skip-lot inspection 3 3.2 Product or service 3 3.3 Lot-by-lot inspection . 3 3.
20、4 Essentially continuous production 3 3.5 Valid major complaint 3 3.6 Reduced inspection . 3 3.7 Skip-lot frequency . 4 3.8 Skip-lot Interrupt 4 4.0 Supplier and product qualification . 4 4.1 Supplier qualification 4 4.2 Product qualification . 4 4.3 Example of product qualification . 5 5.0 Skip-lot
21、 procedures . 5 5.1 Determining the initial skip-lot inspection frequency 6 5.2 Examples of initial frequency determination 6 5.3 Reducing the frequency of inspection . 7 5.4 Lot selection procedures (States 2 and 3) 7 5.5 Interrupt procedures . 8 5.6 Re-qualification procedures . 8 5.7 Disqualifica
22、tion 9 6.0 Supplier responsibilities . 9 7 .0 inspection authority and responsible authority responsibilities 10 8.0 characteristics of the skip-lot procedures .11 Annex A Summary of options . 12 Annex B Procedures for random selection at specified inspection frequencies 13 Annex c Factors used in d
23、eciding between skip-lot inspection and reduced inspection 14 Bibliography 21 viiASQ/ANSI S1 2012 viii Foreword This Foreword is not a part of the American National Standard ASQ/ANSI S1-2012, An attribute skip-lot sampling program. The purpose of this publication is to provide procedures, for reduci
24、ng the inspection effort on products submitted by those suppliers who have demonstrated their ability to control. In an effective manner, all facets of quality and who consistently produce lots which meet requirements. Inspection may take place at the suppliers or purchasers locations or at an inter
25、face between operations of a production process. The skip-lot procedures are designed to be used with the attribute lot-by-lot plans described in ANSI/ASQ Z1 .4. The standard was designed to address four major issues: 1) The number of lots inspected prior to entering the skip-lot state; 2) The numbe
26、r of lots inspected in the skip-lot state between a shift in quality and the detection of the quality shift, with the result of detection being a switch to an interrupt state where lot-by-lot inspection is temporarily reinstated; 3) The characteristics of the interrupt state during which less string
27、ent qualification requirements are used to reinstate full skip-lot inspection; 4) The management capabilities of the supplier. The last issue is important because a working skip-lot program requires confidence in the suppliers capabilities and integrity. A series of enhancements to this standard (An
28、nexes A, B, and C) augment the usability of the standard by outlining procedures for tailoring to the users specific situation, by describing a simple method of random selection, and by providing criteria for deciding between skip-lot inspection and reduced inspection under ANSI/ASQ Z1 .4. Comments
29、concerning this standard are welcome and will be considered in future standards development. Comments should be sent to the Standards Administrator, ASQ, 600 N. Plankinton Ave., P .O. Box 3005, Milwaukee, WI 53201-3005. Writers and Editors: In preparing the 1987 and 1996 versions of this standard, C
30、hairman B. S. Liebesman was assisted by the members of the ASQ Statistics Division and the following major contributors: Sherman Babcock, Acheson Duncan, Dennis J. G. Farlie, A. Blanton Godfrey, Greg Gruska, Y oichi Kato, Bernard Saperstein, Poul Thyregod, Joe Troxell, Joe Tsiakals, Harrison M. Wads
31、worth, and Tsuneo Y okoh. The 2012 version of this standard was prepared by the S1 Writing Group of the ASQ Statistics Division consisting of the following members: Aridaman Jain (chair), Jack Keyser, Ed Shecter, and Ken Stephens. We would like to acknowledge the assistance received from Burton S. L
32、iebesman and Ed Schilling. We are also grateful to Jack West for providing constructive comments on a draft of the 2005 version that were addressed in the final version.1 ASQ/ANSI S1 2012 1.0 introduction This publication is intended to be used only in conjunction with the latest version of ANSI/ASQ
33、 Z1 .4. There are two restrictions on the use of the ANSI/ASQ Z1 .4 1procedures in conjunction with this publication: a) Multiple sampling plans are not to be used during States 2 and 3 of this publication, and b) It is strongly recommended that sampling plans with acceptance numbers of zero not be
34、used during States 2 and 3 of this publication. 1.1 Scope and purpose This standard defines a generic attribute skip-lot sampling program. The purpose of this publication is to provide procedures, for reducing the inspection effort on products submitted by those suppliers who have demonstrated their
35、 ability to control, in an effective manner, all facets of quality and who consistently produce lots which meet requirements. Inspection may take place at the suppliers or purchasers locations or at an interface between operations of a production process. The skip-lot procedures are designed to be u
36、sed with the attribute lot-by-lot plans described in ANSI/ASQ Z1 .4. The skip-lot program described in this standard is based on papers by Liebesman shown in section 2.0. Skip-Lot sampling was originally developed by Dodge. For a discussion of the Dodge plans, see references Dodge (1955), Dodge and
37、Perry (1971), Schilling (1982), and Stephens (2001) cited in the Bibliography. 1.2 Field of application When specified by the purchaser, this standard may be referenced in a purchasing or specification contract, inspection instruction, or other contractual documents. The responsible authority may be
38、 the customer or the suppliers department responsible for inspection or, the cognizant government agency. The inspection authority may be the responsible authority or an organization delegated to conduct the inspection program. This standard defines a generic attribute skip-lot sampling program. How
39、ever, every product has its own environment and characteristics. Throughout this standard, options are provided in recognition of the fact that the supplier and responsible authority should select the appropriate options to meet the specific needs of the product and its environment. All choices as a
40、 result of this tailoring should be specified in a written document. The options are noted in the text with default values. Annex A contains a summary of these options. The procedures designated in this publication are applicable to but not limited to, inspection of the following: a) End items such
41、as complete units or sub-assemblies; b) Components and raw materials; 1 Referred to as ANSI Z1 .4 or Z1 .4 in the remainder of this standard. international StandardASQ/ANSI S1 2012 2 c) Services; d) Materials in process; e) Supplies in storage; f) Data or records; g) Administrative procedures; and h
42、) Software These procedures are intended only for a continuing series of lots or batches 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 the lots not inspected are of the same quality as the ones inspe
43、cted. This publication shall be used only for characteristics inspected by attributes as designated in Z1 .4. Its application differs from that of reduced inspection in Z1 .4. With respect to the inspection of multiple characteristics, the skip-lot procedures shall follow the same principles used in
44、 the associated Z1 .4 program. Reduced Inspection is a feature of Z1 .4 permitting smaller sample sizes than used in normal inspection. It may be used while the product is in the lot-by-lot inspection state or skip-lot interrupt state, but shall not be used during the skip-lot inspection state (see
45、Sections 5.4 and 5.5). Skip-lot sampling may be used in place of reduced inspection if it is more cost effective to do so (see Section 7 .0). 2.0 r eferences Basic definitions may be found in the following standards: ANSI/ISO/ASQ 3534-2, Statistics Vocabulary and symbols Part 2: Applied statistics A
46、NSI/ASQ Z1 .4, Sampling procedures and tables for inspection by attributes The statistical characteristics of the skip-lot program described in this standard are discussed in the following references: Liebesman, Burton S. and Saperstein, Bernard, A Proposed Attribute Skip-Lot Sampling Program, Journ
47、al of Quality T echnology, vol. 15, no. 3, July; 1983, pp. 130-140 Liebesman, Burton S., The Development of an Attribute Skip-Lot Sampling Standard Frontiers in Statistical Quality Control, vol. 3, 1987 , pp. 3-233 ASQ/ANSI S1 2012 3.0 t erms and definitions Terminology and definitions are in accord
48、ance with ANSI/ISO/ASQ 3534-2 and ANSI Z1 .4. 3.1 Skip-lot inspection Skip-Lot Inspection is an acceptance sampling procedure in which some lots in a series are accepted without inspection (other than possible spot checks) when the sampling results for a stated number of immediately preceding lots m
49、eet stated criteria as given in Section 5.1 . 3.2 Product or service The Product or service for which this program is applicable is given in Section 2.1 3.3 lot-by-lot inspection Lot-by-lot inspection is inspection of product submitted in a series of lots. A sample is selected from each lot and inspected using attribute AQL (Acceptable Quality Limit) Sampling procedures described in ANSI Z1 .4. 3.4 essentially continuous production Essentially continuous production is production at a steady rate. Production shall be considered essentially continuous i
