1、BRITISH STANDARDBS EN 60812:2006Analysis techniques for system reliability Procedure for failure mode and effects analysis (FMEA) The European Standard EN 60812:2006 has the status of a British StandardICS 03.120.01; 03.120.30; 21.020g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g
2、51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 60812:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2006 BSI 2006ISBN 0 580 47913 7Natio
3、nal forewordThis British Standard is the official English language version of EN 60812:2006. It was derived by CENELEC from IEC 60812:2006. It supersedes BS 5760-5:1991 which is withdrawn.The UK participation in its preparation was entrusted by Technical Committee DS/1, Reliability and terotechnolog
4、y, to Subcommittee DS/1/1, Dependability, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement international or European publications referred to in this document ma
5、y be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users a
6、re responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, an
7、d keep UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 47 and a back cover.The BSI copyright notice displayed in this document indi
8、cates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARD EN 60812 NORME EUROPENNE EUROPISCHE NORM May 2006 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr
9、Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60812:2006 E ICS 03.120.01; 03.120.30; 21.020 Supersedes HD 485 S1:1987English version Analy
10、sis techniques for system reliability Procedure for failure mode and effects analysis (FMEA) (IEC 60812:2006) Techniques danalyse de la fiabilit du systme Procdure danalyse des modes de dfaillance et de leurs effets (AMDE) (CEI 60812:2006) Analysetechniken fr die Funktionsfhigkeit von Systemen Verfa
11、hren fr die Fehlzustandsart- und -auswirkungsanalyse (FMEA) (IEC 60812:2006) This European Standard was approved by CENELEC on 2006-03-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a na
12、tional standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version
13、 in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech Repu
14、blic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Foreword The text of document 56/1072/FDIS, fut
15、ure edition 2 of IEC 60812, prepared by IEC TC 56, Dependability, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60812 on 2006-03-01. This European Standard supersedes HD 485 S1:1987. The main changes from HD 485 S1:1987 are as follows: introduction of the failure m
16、odes effects and criticality concepts; inclusion of the methods used widely in the automotive industry; added references and relationships to other failure modes analysis methods; added examples; guidance on advantages and disadvantages of different FMEA methods. The following dates were fixed: late
17、st date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2006-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2009-03-01 Annex ZA has been added by CENELEC. _ Endorsem
18、ent notice The text of the International Standard IEC 60812:2006 was approved by CENELEC as a European Standard without any modification. _ EN 60812:2006 2 3 EN 60812:2006 CONTENTS 1 Scope 5 2 Normative references .5 3 Terms and definitions .5 4 Overview7 4.1 Introduction .7 4.2 Purpose and objectiv
19、es of the analysis.8 5 Failure modes and effects analysis .9 5.1 General considerations 9 5.2 Preliminary tasks .10 5.3 Failure mode, effects, and criticality analysis (FMECA).20 5.4 Report of analysis27 6 Other considerations 29 6.1 Common-cause failures .29 6.2 Human factors .29 6.3 Software error
20、s30 6.4 FMEA regarding consequences of system failure30 7 Applications30 7.1 Use of FMEA/FMECA 30 7.2 Benefits of FMEA.32 7.3 Limitations and deficiencies of FMEA .32 7.4 Relationships with other methods.33 Annex A (informative) Summary of procedures for FMEA and FMECA.35 Annex B (informative) Examp
21、les of analyses 39 Annex ZA (normative) Normative references to international publications with their corresponding European publications47 Bibliography .46 Figure 1 Relationship between failure modes and failure effects in a system hierarchy 12 Figure 2 Analysis flowchart 19 Figure 3 Criticality ma
22、trix .23 Figure A.1 Example of the format of an FMEA worksheet38 Figure B.1 FMEA for a part of automotive electronics with RPN calculation .40 Figure B.2 Diagram of subsystems of a motor generator set41 Figure B.3 Diagram of enclosure heating, ventilation and cooling systems.42 Figure B.4 FMEA for s
23、ub-system 20 .43 Figure B.5 Part of a process FMECA for machined aluminium casting .45 EN 60812:2006 4 Table 1 Example of a set of general failure modes14Table 2 Illustrative example of a severity classification for end effects.17 Table 3 Risk/criticality matrix24 Table 4 Failure mode severity 25 Ta
24、ble 5 Failure mode occurrence related to frequency and probability of occurrence.25 Table 6 Failure mode detection evaluation criteria 26 Table 7 Example of a set of failure effects (for a motor vehicle starter)28 Table 8 Example of a failure effects probability.28 Table B.1 Definition and classific
25、ation of the severity of the effects of failures on the complete M-G system .41 5 EN 60812:2006 ANALYSIS TECHNIQUES FOR SYSTEM RELIABILITY PROCEDURE FOR FAILURE MODE AND EFFECTS ANALYSIS (FMEA) 1 Scope This International Standard describes Failure Mode and Effects Analysis (FMEA) and Failure Mode, E
26、ffects and Criticality Analysis (FMECA), and gives guidance as to how they may be applied to achieve various objectives by providing the procedural steps necessary to perform an analysis; identifying appropriate terms, assumptions, criticality measures, failure modes; defining basic principles; prov
27、iding examples of the necessary worksheets or other tabular forms. All the general qualitative considerations presented for FMEA will apply to FMECA, since the latter is an extension of the other. 2 Normative references The following referenced documents are indispensable for the application of this
28、 document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60300-3-1:2003, Dependability management Part 3-1: Application guide Analysis techniques for dependability Guide on methodolo
29、gy IEC 61025, Fault tree analysis (FTA) IEC 61078, Analysis techniques for dependability Reliability block diagram method 3 Terms and definitions For the purposes of this document, the following definitions apply. 3.1 item any part, component, device, subsystem, functional unit, equipment or system
30、that can be individually considered NOTE 1 An item may consist of hardware, software or both, and may also in particular cases include people. NOTE 2 A number of items, e.g. a population of items or a sample, may itself be considered as an item. IEV 191-01-01 EN 60812:2006 6 A process can also be de
31、fined as an item which carries out a predetermined function and for which a process FMEA or FMECA is carried out. Normally, a hardware FMEA does not address people and their interactions with hardware/software, while a process FMEA normally includes actions of people. 3.2 failure termination of the
32、ability of an item to perform a required function IEV 191-04-01 3.3 fault state of an item characterized by the inability to perform a required function, excluding the inability during preventive maintenance or other planned actions, or due to lack of external resources NOTE 1 A fault is often the r
33、esult of a failure of the item itself, but may exist without prior failure. IEV 191-05-01 NOTE 2 In this document “fault” is used interchangeably with the term “failure” for historical reasons. 3.4 failure effect consequence of a failure mode in terms of the operation, function or status of the item
34、 3.5 failure mode manner in which an item fails 3.6 failure criticality combination of the severity of an effect and the frequency of its occurrence or other attributes of a failure as a measure of the need for addressing and mitigation 3.7 system set of interrelated or interacting elements NOTE 1 I
35、n the context of dependability, a system will have a) defined purposes expressed in terms of required functions; b) stated conditions of operation use (see 191-01-12); c) a defined boundary. NOTE 2 The structure of a system is hierarchical. ISO 9000:2000 3.8 failure severity significance or grading
36、of the failure modes effect on item operation, on the item surrounding, or on the item operator; failure mode effect severity as related to the defined boundaries of the analysed system 7 EN 60812:2006 4 Overview 4.1 Introduction Failure Modes and Effect Analysis (FMEA) is a systematic procedure for
37、 the analysis of a system to identify the potential failure modes, their causes and effects on system performance (performance of the immediate assembly and the entire system or a process). Here, the term system is used as a representation of hardware, software (with their interaction) or a process.
38、 The analysis is successfully performed preferably early in the development cycle so that removal or mitigation of the failure mode is most cost effective. This analysis can be initiated as soon as the system is defined enough to be presented as a functional block diagram where performance of its el
39、ements can be defined. FMEA timing is essential; if done early enough in the development cycle, then incorporating the design changes to overcome deficiencies identified by the FMEA may be cost effective. It is therefore important that the FMEA task and its deliverables be incorporated into the deve
40、lopment plan and schedule. Thus, FMEA is an iterative process that takes place coincidentally with design process. FMEA is applicable at various levels of system decomposition from the highest level of block diagram down to the functions of discrete components or software commands. The FMEA is also
41、an iterative process that is updated as the design develops. Design changes will require that relevant parts of the FMEA be reviewed and updated. A thorough FMEA is a result of a team composed of individuals qualified to recognize and assess the magnitude and consequences of various types of potenti
42、al inadequacies in the product design that might lead to failures. Advantage of the team work is that it stimulates thought process, and ensures necessary expertise. FMEA is considered to be a method to identify the severity of potential failure modes and to provide an input to mitigating measures t
43、o reduce risk. In some applications however, FMEA also includes an estimation of the probability of occurrence of the failure modes. This enhances the analysis by providing a measure of the failure modes likelihood. Application of FMEA is preceded by a hierarchical decomposition of the system (hardw
44、are with software, or a process) into its more basic elements. It is useful to employ simple block diagrams to illustrate this decomposition (IEC 61078). The analysis then starts with lowest level elements. A failure mode effect at a lower level may then become a failure cause of a failure mode of a
45、n item in the next higher level. The analysis proceeds in a bottom-up fashion until the end effect on the system is identified. Figure 1 illustrates this relationship. FMECA (Failure Modes, Effects and Criticality Analysis) is an extension to the FMEA to include a means of ranking the severity of th
46、e failure modes to allow prioritization of countermeasures. This is done by combining the severity measure and frequency of occur-rence to produce a metric called criticality. The principles of an FMEA may be applied outside of engineering design. FMEA procedure can be applied to a manufacturing or
47、any other work process such as in hospitals, medical laboratories, school systems, or others. When FMEA is applied to a manufacturing process, EN 60812:2006 8 this procedure is known in industry as the Process FMEA, or PFMEA. For an FMEA to be effective, adequate resources for a team work have to be
48、 committed. A thorough understanding of the system under analysis may not be essential for a preliminary FMEA. With development of design, a detailed failure mode analysis requires thorough knowledge of the design performance and its specifications. Complex engineering designs usually require the in
49、volvement of multiple areas of design expertise (e.g. mechanical engineering, electrical engineering, systems engineering, software engineering, maintenance support, etc). FMEA generally deals with individual failure modes and the effect of these failure modes on the system. Each failure mode is treated as independent. The procedure is therefore unsuitable for consideration of dependent failures or failures resulting from a sequence of events.
