1、BSI Standards PublicationBS 5760-0:2014Reliability of systems,equipment andcomponents Part 0: Guide to reliability andmaintainabilityPublishing and copyright informationThe BSI copyright notice displayed in this document indicates when the documentwas last issued. The British Standards Institution 2
2、014Published by BSI Standards Limited 2014ISBN 978 0 580 72465 7ICS 03.120.01; 21.020; 29.020The following BSI references relate to the work on this document:Committee reference DS/1Draft for comment 13/30232639Publication historyFirst published October 1986Second (current) edition March 2014Amendme
3、nts issued since publicationDate Text affectedBS 5760-0:2014 BRITISH STANDARDContentsForeword ii1 Scope 12 Terms and definitions and abbreviations 13 Basic principles of reliability 34 Basic principles of maintainability 55 Managing reliability and maintainability 66 Availability, reliability and ma
4、intainability in the life cycle 77 Use of reliability and maintainability in tenders and contracts 168 Interaction with related disciplines 18AnnexesAnnex A (informative) Failure patterns 22Annex B (informative) Availability 24Annex C (informative) Integrated logistic support 25Bibliography 26List o
5、f figuresFigure 1 Project life cycle 8Figure 2 Achieving high availability 13Figure A.1 Failure pattern: constant failure rate 22Figure A.2 Failure pattern: infant mortality 22Figure A.3 Failure pattern: wear-in 23Figure A.4 Failure pattern: wear out 23Figure A.5 Failure pattern: increasing 23Figure
6、 A.6 Failure pattern: bath-tub curve 24List of tablesTable A.1 Failure pattern categories and frequency of occurrenceA)24Summary of pagesThis document comprises a front cover, an inside front cover, pages i to iv,pages 1 to 26, an inside back cover and a back cover.BRITISH STANDARD BS 5760-0:2014 Th
7、e British Standards Institution 2014 iForewordPublishing informationThis British Standard is published by BSI Standards Limited, under licence fromThe British Standards Institution, and came into effect on 31 March 2014. It wasprepared by Technical Committee DS/1, Dependability. A list of organizati
8、onsrepresented on this committee can be obtained on request to its secretary.SupersessionThis part of BS 5760 supersedes BS 5760-0:1986, which is withdrawn.Relationship with other publicationsThe following parts of BS 5760 have been published or are in preparation: Part 0: Guide to reliability and m
9、aintainability; Part 2: Guide to the assessment of reliability; Part 8: Guide to assessment of reliability of systems containing software; Part 10: Guide to reliability testing; Part 12: Guide to the presentation of reliability, maintainability andavailability predictions; Part 13: Guide to reliabil
10、ity test conditions for consumer equipment; Part 18: Guide to the demonstration of dependability requirements Thedependability case; Part 24: Guide to the integration of risk techniques in the inspection andtesting of complex systems.Information about this documentThis is a full revision of BS 5760-
11、0 and its changes reflect current practices. Whileaddressing system and equipment level reliability and maintainability, many ofthe techniques described in the different parts of BS 5760 can also be applied atthe component level.Use of this documentAs a guide, this British Standard takes the form of
12、 guidance andrecommendations. It should not be quoted as if it were a specification or a codeof practice and claims of compliance cannot be made to it.It has been assumed in the preparation of this British Standard that theexecution of its provisions will be entrusted to appropriately qualified ande
13、xperienced people, for whose use it has been produced.Presentational conventionsThe guidance in this standard is presented in roman (i.e. upright) type. Anyrecommendations are expressed in sentences in which the principal auxiliaryverb is “should”.Commentary, explanation and general informative mate
14、rial is presented insmaller italic type, and does not constitute a normative element.BRITISH STANDARDBS 5760-0:2014ii The British Standards Institution 2014Contractual and legal considerationsThis publication does not purport to include all the necessary provisions of acontract. Users are responsibl
15、e for its correct application.Compliance with a British Standard cannot confer immunity from legalobligations.BRITISH STANDARD BS 5760-0:2014 The British Standards Institution 2014 iiiIntroductionReliability and maintainability are vital qualities of any system or product. Whenassessing how good a s
16、ystem or product is, the end user considers fourcharacteristics: how much did it cost, how well does it perform when it isworking, how often does it break down and how easy is it to mend when it hasbroken down. A successful product or system strikes the correct balancebetween these considerations. T
17、his standard provides guidance on how to assessand control the last two considerations, which are formally named reliability andmaintainability, respectively.When a product fails, it as a minimum inconveniences the user as a result ofdirect costs involved in undertaking repair and loss of use of the
18、 product. In thecase of systems with a safety implication, unexpected failure can have far moreserious consequences. The outcome of failures can range from loss of reputationthrough direct and indirect financial penalties to legal action. As reliability andmaintainability are inherent design charact
19、eristics, it is essential that therequired characteristics are identified as early in the design process as possible,when the other performance criteria are also being set. If they are notconsidered at this stage, it is likely that the product will not be satisfactory.The activities described within
20、 this standard normally form part of anorganizations asset management strategy and are therefore aligned to, andconsistent with, the organizational objectives.BRITISH STANDARDBS 5760-0:2014iv The British Standards Institution 20141 ScopeThis part of BS 5760 gives guidance on the basic principles of
21、reliability andmaintainability that are applicable to any business model.It is particularly applicable to reliability and maintainability in the design,manufacturing, management and decommissioning of products, equipment,services, plant or structures, and gives guidance on matters of common interest
22、to any business supplying or purchasing products, services, plant or structures.This part of BS 5760 provides all managers and engineers involved in thespecification, design, development, manufacture, acceptance and use ofengineering artefacts with guidance on how to manage reliability andmaintainab
23、ility effectively and develop an auditable record of activities. Thisstandard is also applicable to students and anyone else who needs tounderstand how to develop, manufacture and support systems and equipmentthat meet the needs of the user by working when required.This part of BS 5760 does not give
24、 guidance on issues relating to safety.However, much of the guidance could also be applied to the production ofsafety cases.NOTE Guidance on component reliability is given in BS CECC 00804.2 Terms and definitions and abbreviationsFor the purposes of this part of BS 5760, the following terms and defi
25、nitionsapply.2.1 active repair timepart of the active maintenance time during which repairs are performed on anitemNOTE This does not take into account any waiting time for maintenance resources.2.2 availabilityability to be in a state to perform as requiredNOTE Availability depends upon the combine
26、d characteristics of the reliability,recoverability, and maintainability of the item, and the maintenance supportperformance.2.3 intrinsic availabilityavailability provided by the design, under ideal conditions of operation andmaintenanceNOTE 1 Delays associated with maintenance, such as logistic an
27、d administrativedelays, are excluded.NOTE 2 Operational availability is determined considering down time due tofailures, outages and associated delays, but excluding external causes.2.4 corrective maintenancemaintenance carried out after fault detection to effect restorationNOTE Corrective maintenan
28、ce of software invariably involves some modification.2.5 dependabilityability to perform as and when requiredNOTE 1 Dependability includes availability, reliability, recoverability, maintainabilityand maintenance support performance, and, in some cases, other characteristics suchas durability, safet
29、y and security.BRITISH STANDARD BS 5760-0:2014 The British Standards Institution 2014 1NOTE 2 Dependability is used as a collective term for the time-related qualitycharacteristics of an item.2.6 failureloss of ability to perform as required, or event that results in a fault state ofthat itemNOTE 1
30、Qualifiers such as catastrophic, critical, major, minor, marginal andinsignificant may be used to categorize failures according to the severity ofconsequences; the choice and definitions of severity criteria depend upon the fieldof application.NOTE 2 Qualifiers such misuse, mishandling and weakness
31、may be used tocategorize failures according to the cause of failure.2.7 functionactivity or feature that an item is required to be capable of doing in order tomeet an operational (user) requirement2.8 integrated logistic supportmanagement process to determine and co-ordinate the provision of all mat
32、erialsand resources required to meet the needs for operation and maintenance2.9 itemsubject being consideredNOTE 1 The item might be an individual part, component, device, functional unit,equipment or system and consist of hardware, software, people or any combinationthereof.NOTE 3 The item is often
33、 comprised of elements that may each be individuallyconsidered.2.10 maintainabilityability to be retained in, or restored to a state to perform as required, undergiven conditions of use and maintenanceNOTE Given conditions include aspects that affect maintainability, such as locationof maintenance,
34、accessibility, maintenance procedures and maintenance resources.2.11 level of maintenanceset of maintenance actions to be carried out at a specified indenture levelSOURCE: BS 4778-3.2:1991, IEC 60050-191:1991, 191-07-062.12 preventive maintenancemaintenance carried out to mitigate degradation and re
35、duce the probability offailure2.13 reliabilityability to perform as required, without failure, for a given time interval, undergiven conditionsNOTE 1 The time interval duration might be expressed in units appropriate to theitem concerned, e.g. calendar time, operating cycles, distance run.NOTE 2 Giv
36、en conditions include aspects that affect reliability, such as mode ofoperation, stress levels, environmental conditions and maintenance.NOTE 3 Reliability may be quantified using appropriate measures.2.14 reliability centred maintenance (RCM)systematic method for determining the respective maintena
37、nce actions andassociated frequencies, based on the probability and consequences of failureBRITISH STANDARDBS 5760-0:20142 The British Standards Institution 2014NOTE 1 RCM uses analysis of modes of failure to select the best defence strategyfor each possible failure mode.NOTE 2 RCM studies may be co
38、nducted at any indenture level of a system, andprovide feedback to initiate modifications of design or procedures to effectimprovements.2.15 reliability growthiterative process for reliability improvement by addressing design andmanufacturing weaknesses2.16 reliability modelmathematical model used f
39、or prediction or estimation of reliability measuresNOTE Modelling techniques may be applied to other characteristics, such asmaintainability and availability.2.17 systemset of inter-related items that collectively fulfil a requirementNOTE 1 A system is considered to have a defined real or abstract b
40、oundary.NOTE 2 External resources (from outside the system boundary) might be requiredfor the system to operate.NOTE 3 A system structure might be hierarchical, e.g. system, subsystem,component.2.18 AbbreviationsFor the purposes of this part of BS 5760, the following abbreviations apply.BIT Built in
41、 testBITE Built in test equipmentDRACAS Data reporting and corrective action systemESS Environmental stress screeningFMECA Failure mode, effects and criticality analysisILS Integrated logistic supportLCC Life cycle costingMART Mean active repair timeMTBF Mean time between failures of the systemRb) m
42、aximum rate of turn; orc) minimum number of communication channels available.The type of parameter to be considered depends upon the specific item and itsintended use.1)Having an element of chance (as opposed to deterministic parameters, which can bemeasured repeatedly).BRITISH STANDARDBS 5760-0:201
43、44 The British Standards Institution 20143.5 ConditionsThe environmental conditions (temperature, pressure, chemical, dust, etc.) inwhich an item is used, stored and transported, and the way in which it isoperated and maintained, can have a major influence on its reliability. Theseconditions should
44、be defined to the design team during the design anddevelopment of an item.NOTE For example, a standard car could not be expected to achieve the samereliability when driven on desert tracks as it would in UK road use; cars intended forsuch use are especially designed for the conditions.3.6 Usage time
45、sThe period of usage in which an item is expected to function should bedetermined as part of the development of requirements (5.2).NOTE For example, the typical flight pattern for an aircraft, a typical day for atransport vehicle, the period between major shut downs for an industrial plant, or a12 m
46、onth period for an eCommerce system.Reliability of items might vary with their age (covering calendar time, usagetime, distance travelled, number of cycles or whatever metric is appropriate).Separate requirements for reliability under different conditions or for differentperiods of time (for instanc
47、e summer or winter use, or periods of continuous useversus intermittent usage) should be identified and related to the relevantfunctions.4 Basic principles of maintainability4.1 GeneralMaintainability is the quantitative assessment of how easily and quicklypreventive maintenance might be performed o
48、r a system restored tofunctionality through corrective maintenance (6.4.5.2). This is dependent uponboth the environment in which maintenance is performed and the resourcesavailable to do so.The considerations associated with maintainability are given in 4.2 and 4.3.4.2 Maintenance contextThese are
49、the conditions under which preventive maintenance or repair isconducted. Factors such as ease of access, maximum allowable downtime,temperature, field or workshop conditions, and lighting and restrictive clothingshould all be defined to the design team if they are externally imposed, orshould be taken into account by the designers in response to the overallreliability and maintainability requirements if not.4.3 Stated procedures and resourcesThe customer or user might put constraints on the resources allowed forpreventive maintenance an
