SAE AS 9138-2018 Aerospace Series - Quality Management Systems Statistical Product Acceptance Requirements.pdf

1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there

2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2018 SAE International All rights reserved. No part of this p

3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497

4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/standards.sae.org/AS9138 AEROSPACE STANDARD AS9138 Issued 2018-01 Supersedes ARP9013 Technically equivalent writi

5、ngs published in all IAQG sectors. Aerospace Series - Quality Management Systems Statistical Product Acceptance Requirements RATIONALE This standard is an upgrade and replacement for the Aerospace Recommended Practice (ARP) 9013-series of documents (i.e., ARP9013, ARP9013/1, ARP9013/2, ARP9013/3, AR

6、P9013/4) prepared and published by the Americas Aerospace Quality Group (AAQG) in 2005. Technically equivalent standards are published in all International Aerospace Quality Group (IAQG) sectors (i.e., Americas, Asia-Pacific, Europe). Reasons for publishing this standard include the following: 1. Qu

7、ality Engineers and planners within many organizations which utilized sampling standards, prior to the publishing of the ARP9013-series of documents, found previous standards difficult to interpret and/or to implement correctly. The IAQG recognized this situation and chartered a committee in 2001 to

8、 develop a new sampling standard. The assignment to write a new statistical standard was given to the Americas sector of the IAQG with the stated strategy that once the new document was published and tested in the AAQG, it would be brought back to the IAQG for global implementation. 2. The ARP9013-s

9、eries of documents was published in 2005 to be simpler than existing legacy standards. It also marked a transition from legacy statistical product acceptance requirement documents that were organized around a measure of producer protection rather than consumer protection. To accomplish this without

10、extreme increases in inspection required the simultaneous introduction of new statistical tools and tables. 3. After experience gained from the initial release of the ARP9013-series of documents, the IAQG believed that the goals of simpler and more effective statistical methods for Quality Engineers

11、 and planners had been achieved, but that further improvements were possible, both in the development of new tools and in providing further detail/clarifications within the writing. 4. Furthermore, there have been changes in the 9100/9110/9120 quality management system standards relative to the lang

12、uage associated to statistical product acceptance. This 9138 standard incorporates those changes. SAE INTERNATIONAL AS9138 Page 2 of 94 FOREWORD To assure customer satisfaction, the aviation, space, and defense industry organizations produce, and continually improve, safe, reliable products that mee

13、t or exceed customer and regulatory authority requirements. The globalization of the aerospace industry and the resulting diversity of regional/national requirements and expectations have complicated this objective. End-product organizations face the challenge of integrating and assuring the quality

14、 of product purchased from suppliers throughout the world and at all levels within the supply chain, while suppliers and processors face the challenge of delivering product to multiple customers having varying quality expectations and requirements. The aerospace industry established the IAQG for the

15、 purpose of achieving significant improvements in quality and safety, and in reduced costs throughout the value stream. This organization includes representation from aerospace companies in the Americas, Asia/Pacific, and Europe. This standard has been prepared by the IAQG. This document standardize

16、s and streamlines, to the greatest extent possible, the requirements and flexible resources on statistical techniques for product acceptance across the diversity of aerospace industry processes. The establishment of common requirements, for use at all levels of the supply-chain by organizations arou

17、nd the world, should result in improved quality and safety, and decreased costs due to the elimination or reduction of organization-unique requirements and the resultant variation inherent in these multiple expectations. SAE INTERNATIONAL AS9138 Page 3 of 94 TABLE OF CONTENTS RATIONALE . 1 FOREWORD

18、. 2 INTRODUCTION . 6 0.1 Paradigm of Quality Requirements and Product Acceptance Plans 6 0.1.1 Engineering . 6 0.1.2 Operations . 7 0.2 Acceptance Method Considerations . 7 1. SCOPE 9 1.1 Purpose . 9 1.2 Application . 9 2. REFERENCES 10 3. TERMS AND DEFINITIONS . 14 4. GENERAL REQUIREMENTS 24 4.1 In

19、troduction to General Requirements 24 4.2 Trained Personnel . 24 4.3 Safety/Critical Characteristics . 24 4.4 Quality Requirements and Parameters . 24 4.4.1 Quality Parameter . 24 4.4.2 Quality Parameter Value . 24 4.4.3 Alternative Quality Plans . 25 4.4.4 Regulatory Requirements . 25 4.5 Selection

20、 of Samples 25 4.6 Consideration of Product and Process Characteristics 25 4.7 Evaluation Systems . 26 4.8 Nonconformances (within the sample) 26 4.9 Statistical Product Acceptance Plans and Records 26 4.10 Alternate Statistical Techniques for Product Acceptance . 26 4.11 Auditing of Statistical Tec

21、hniques for Product Acceptance 26 5. REQUIRED INFORMATION TO BE DOCUMENTED 27 5.1 Documented Procedure Requirements . 27 5.2 Initial Reliability Requirement or Quality Parameter Values for Product Acceptance 27 5.3 Assigning Responsibilities 27 5.4 Assigning Where Applied 27 5.5 Establishing a Train

22、ing Program . 27 5.6 Controlling Nonconformances . 27 5.7 Monitoring Performance and Effectiveness 27 5.8 Defining Adjustments to Inspection Frequency 27 5.9 Customer Approval of Procedures and Plans . 27 6. REQUIREMENTS FOR ACCEPTING PRODUCT BY INDIVIDUAL LOTS . 28 6.1 General Requirements for Indi

23、vidual Lot Sampling 28 6.2 Quality Parameters for Individual Lot Sampling 28 6.2.1 Delivered Product Conformance Probability Parameters . 28 6.2.2 Probability of Acceptance Parameters 28 6.3 Sample Sizes for Individual Lots . 28 SAE INTERNATIONAL AS9138 Page 4 of 94 7. REQUIREMENTS FOR ACCEPTING PRO

24、DUCT PRODUCED UNDER SWITCHING RULES . 29 7.1 General Requirements for Switching Rules 29 7.2 Background Information for Switching Rules 29 7.3 Quality Parameter with Switching Rules . 29 7.4 Requirements for Accepting Product with Switching Rules 29 7.4.1 Sampling Documentation 29 7.4.2 General Cond

25、itions . 29 7.4.3 Sampling Plan Criteria 30 7.4.4 Qualification Criteria for Sampling 30 7.5 Requirements for Accepting Product by Variables Sampling Plans Using Switching Rules 30 7.5.1 Variables Sampling Application Limits 30 7.5.2 Evaluating Lot Quality . 30 7.5.3 Related Requirements 30 8. REQUI

26、REMENTS FOR ACCEPTING PRODUCT PRODUCED UNDER PROCESS CONTROLS 31 8.1 General Process Control Requirements . 31 8.1.1 Data . 31 8.1.2 Reducing Inspection with Process Controls 31 8.1.3 Measurement Systems . 31 8.1.4 Training Program 31 8.1.5 Process Control Points 31 8.1.6 Process Control Acceptance

27、Plans and Records . 32 8.1.7 Unbiased Sampling . 32 8.1.8 Time or Production Order Sequence 32 8.1.9 Data Retention Plan 32 8.1.10 Periodic Internal Audits . 32 8.1.11 Retrievability System . 32 8.1.12 Limiting Errors in Measurement and Recording . 32 8.1.13 Evaluating Effects of Corrective Actions

28、. 32 8.2 Statistical Process Control 32 8.2.1 Methods 32 8.2.2 Location and Dispersion 32 8.2.3 Basis for Control Limits . 33 8.2.4 Basis for Stability . 33 8.2.5 Investigation 33 8.2.6 Violation of Stability . 33 8.2.7 Re-Evaluation of Stability and Capability 33 8.2.8 Capability and Process Contro

29、l . 34 8.2.9 Process Monitoring Frequency . 34 8.3 Variation Restrictions 35 8.4 Process Parameter Controls . 35 9. ADDITIONAL REQUIREMENTS FOR ACCEPTING PRODUCTS BASED ON CONTINUOUS SAMPLING, SKIP-LOT SAMPLING, OR METHODS FOR SPECIAL CASES . 36 9.1 Continuous Sampling 36 9.1.1 Quality Parameters fo

30、r Continuous Sampling . 36 9.1.2 Inspection Sequence . 36 9.1.3 General Conditions . 36 9.1.4 Supply Chain Management Handbook Continuous Sampling Tables 36 9.2 Skip-Lot Sampling . 36 9.2.1 General Conditions for Skip-Lot Sampling 36 9.2.2 Quality Protection Equivalency . 36 9.2.3 Considerations for

31、 Subsequent Lots . 37 9.3 Sampling Strategies for Special Cases . 37 9.3.1 Special Sampling Customer Approvals . 37 9.3.2 Special Case Statistical Validity 37 9.3.3 Predicting Quality from Correlated Variables 37 9.3.4 Continuous Manufacturing Process First and Last Unit for a Lot Produced 37 9.3.5

32、Sequential Sampling . 38 9.4 Other Methods for Special Cases . 38 SAE INTERNATIONAL AS9138 Page 5 of 94 10. NOTES 39 10.1 Revision Indicator 39 APPENDIX A GUIDELINES FOR ASSIGNING INITIAL RELIABILITY REQUIREMENT QUALITY LEVELS . 40 APPENDIX B ACRONYM LOG . 43 APPENDIX C MATHEMATICS FOR ACCEPTING PRO

33、DUCT UNDER LOT-BY-LOT INSPECTION 45 APPENDIX D GUIDELINES AND RECOMMENDATIONS FOR SUCCESSFUL IMPLEMENTATION OF STATISTICAL PRODUCT ACCEPTANCE METHODS . 59 APPENDIX E DISCUSSION ON THE TECHNICAL RATIONALE AND HISTORY OF THE RELATIONSHIP OF QUALITY PARAMETERS TO RELIABILITY . 68 APPENDIX F GUIDELINES

34、FOR CHOOSING A STATISTICAL PRODUCT ACCEPTANCE TECHNIQUE AND QUALITY PARAMETER 72 APPENDIX G GUIDELINES AND RECOMMENDATIONS FOR ACCEPTING PRODUCT BY INDIVIDUAL LOTS 75 APPENDIX H GUIDELINES FOR SOME SPECIAL ACCEPTANCE METHODS 80 APPENDIX I GUIDELINES AND RECOMMENDATIONS FOR ACCEPTING PRODUCT PRODUCED

35、 UNDER SWITCHING RULES 86 APPENDIX J GUIDELINES AND RECOMMENDATIONS FOR ACCEPTING PRODUCT PRODUCED UNDER PROCESS CONTROLS . 88 APPENDIX K GUIDELINES AND RECOMMENDATIONS FOR ACCEPTING PRODUCTS BASED ON CONTINUOUS SAMPLING 91 FIGURE 1 ENGINEERING AND OPERATIONS INPUTS INTO PRODUCT ACCEPTANCE PLAN . 6

36、FIGURE 2 9138 SECTION SELECTION GUIDE . 7 FIGURE 3 TYPICAL STATISTICAL PROCESS CONTROL CHART DEPICTING CONTROL LIMITS, WARNING LIMITS, AND ZONES 33 FIGURE C1 AVERAGE OUTGOING QUALITY OPERATING CHARACTERISTIC CURVE WITH AVERAGE OUTGOING QUALITY LIMIT AND INITIAL RELIABILITY REQUIREMENT LIMIT . 53 FIG

37、URE C2 AVERAGE OUTGOING QUALITY OPERATING CHARACTERISTIC CURVE WHERE FAILED LOTS ARE SCRAPPED . 54 FIGURE C3 POINTS ON AVERAGE OUTGOING QUALITY OPERATING CHARACTERISTIC CURVE FOR MEETING INITIAL RELIABILITY REQUIREMENT WHEN SALVAGING SAMPLE UNITS FROM FAILED LOTS . 55 FIGURE C3A THE AVERAGE OUTGOING

38、 QUALITY MEETS (1-IRR) 55 FIGURE C3B THE AVERAGE OUTGOING QUALITY AT THE YIELD CONFIDENCE LIMIT MEETS (1-IRR) . 55 FIGURE G1 FLOWCHART FOR IDENTIFYING LOT SAMPLING METHOD . 77 FIGURE H1 EXAMPLE GRAPHIC CONFIDENCE LEVEL TO MATCH INITIAL RELIABILITY REQUIREMENT . 82 FIGURE K1 ILLUSTRATION OF CSP-1 CON

39、TINUOUS SAMPLING . 93 TABLE 1 ACCEPTABLE QUALITY LEVEL TO AVERAGE OUTGOING QUALITY LIMIT CONVERSION 25 TABLE 2 TRUE Cpk REQUIREMENTS 34 TABLE A1 MINIMUM PROBABILITY OF CONFORMANCE VALUES . 41 TABLE C1 TABLE OF MATHEMATICAL VARIABLES 45 TABLE C2 MINIMUM SAMPLE SIZES NEEDED FOR A YIELD CONFIDENCE LEVE

40、L WHEN NO NONCONFORMITIES ARE DETECTED . 47 TABLE C3 EXPECTED ESCAPEMENTS AND DELIVERED UNITS 51 TABLE C4 AVERAGE OUTGOING QUALITY FORMULAS FOR LOT SAMPLING CATEGORIES . 52 TABLE C5 AVERAGE OUTGOING QUALITY FORMULAS FOR EXAMINING LOT SIZE LIMITS . 53 TABLE C6 EXPECTED ESCAPEMENTS AND DELIVERED UNITS

41、 WHEN TESTS ARE DESTRUCTIVE 56 TABLE E1 FORMULAS FOR CONVERTING QUALITY PARAMETER SPECIFICATIONS INTO AN INITIAL RELIABILITY REQUIREMENT 70 TABLE E2 CONVERSION OF ACCEPTABLE QUALITY LEVEL SPECIFICATION TO AVERAGE OUTGOING QUALITY LIMIT 71 TABLE F1 GUIDELINES TO DETERMINE INSPECTION LOGISTICS 72 TABL

42、E F2 QUALITY PARAMETER VALUE TO INITIAL RELIABILITY REQUIREMENT VALUE COMPARISONS . 73 TABLE H1 EXAMPLE COMPUTATIONS FOR EXPECTED OUTGOING QUALITY 84 TABLE I1 EXAMPLE ACCEPTABLE QUALITY LEVEL VALUES TO USE TO MEET A REQUIRED 3% AVERAGE OUTGOING QUALITY LIMIT 86 TABLE K1 VALUES OF “i” FOR CHOICE OF “

43、f” AND AVERAGE OUTGOING QUALITY LIMIT 94 SAE INTERNATIONAL AS9138 Page 6 of 94 INTRODUCTION This standard establishes the general requirements applicable to any method of statistical product acceptance to reduce inspection costs while still assuring acceptable quality. There is no single specific pl

44、an that can be considered best suited for all applications or processes. This document applies only to statistical methods used for product acceptance and does not apply to statistical methods that are not related to product acceptance. Many companies use excellent statistical methods solely to moni

45、tor and to improve their product quality, and those methods are not subject to the requirements of this document. Products which are eligible for the methods defined in this standard include, but are not limited to: end items, cast, forged, wrought, machined, fabricated, plastic, molded, powdered me

46、tal, or stamped components and raw material; electronic, electrical, and mechanical components. 0.1 Paradigm of Quality Requirements and Product Acceptance Plans Figure 1 shows how requirements and acceptance strategies come together to develop a product acceptance plan. Figure 1 - Engineering and o

47、perations inputs into product acceptance plan 0.1.1 Engineering Each product is engineered to meet functionality and reliability goals. Engineering provides requirements that are needed to meet the goals. Assessment of the goals involves statistics. To compare the goals with engineering requirements

48、 requires a statistical benchmark. This document expresses the engineering requirement as an Initial Reliability Requirement (IRR) or Inspection Reliability Requirement. The IRR defines a minimum acceptable outgoing yield or probability of conformance. It is recommended by regulatory authorities tha

49、t, “Engineering and manufacturing organizations should participate in the review, implementation, and maintenance of statistical quality/process control techniques used for product or article acceptance” reference Federal Aviation Administration (FAA) Advisory Circular (AC) 21-43. If Engineering does not provide a specific protection value (e.g., IRR), then the values in Appendix A (see Table A1) are provided as conventional levels