Procedures for Performing a Failure Mode, Effects and ...

1 ,_ . I :_AMSC N3074 MIL-STD-1629A24 NOVEMBER 1980~-SUPERSEDINGMIL-STD-1629 (SHIPS)1 NOVEMBER 1974 MIL-STD-2070 (AS)12 JUNE 1977 MILITARY STANDARDPROCEDURES FOR PERFORMINGA Failure MODE, Effects AND CRlTlCALliV ANALYSISl=SC RELIMIL-STD-1629 ADEPARTMENT OF DEFENSEW ashington, DC 20301 Procedures for Performing a Failure Mode, Effects , and Military Standard is approved for use by all Departmentsand Agencies of the Department of comments (recommendations, additions, deletions)and any pertinent data which may be of use in improving thisdocument should be addressed to.

2 Commanding Officer, EngineeringSpecifications and Standards Department (Code 93), Naval AirEngineering Center, Lakehurst, NJ 08733, by using the self-addressed Standardization Document Improvement Proposal (DDForm 1426) appearing at the end of this document or by ,-STD- 1629 AFOREWORDThe Failure mode, Effects ,Iand criticality analysis (FMFCA) is an essentialfunytion in design,from concept through development. To be effective,the8mCA'must be iterative to correspond with the nature of the designprobess extent of effort and sophistication of approachused in the FMECA will be dependent upon the nature and requirements ofthe individual makes it necessary to tailor the requirementsfor an FMECA to each individual requires that,regardless of the degree of sophistication.

3 The FMECA must contributemeaningfully to program properly performed FMECA is invaluableto those who are responsible for making program decisions regarding thefeasibility and adequacy of a design usefulness of the FMECA as a design tool and in the decision makingprocess is dependent upon the effectiveness with which problem informationis communicated for early design the greatestcriticism of the FMECA has been its limited use in improving chief causes for this have been untimeliness and the isolated performanceof the FMECA without adequate inputs to the design perhaps the most important factor in differentiating between effectiveand ineffective implementation of the the objective of anFMECA is to identify all modes of Failure within a system design, itsfirst purpose is the early identification of all catastrophic and criticalfailure possibilities so they can be eliminated or minimized throughdesign correction at the earliest possible.

4 The FMECA should be initiated as soon as preliminary design information is availableat the higher system levels and extended to the lower levels as moreinformation becomes available on the items in the FMECA is an essential reliability task, it also providesinformation for other use of the FMECA is called for inmaintainability, safety analysis,survivability and vulnerability,logistics support analysis,maintenance plan analysis, and for failuredetection and isolation subsystem coincident use must be aconsideration in planning the FMECA effort to prevent the proliferationof requirements and the duplication of efforts within the same ,-STD- of of analysis (CA).

5 Damage damage mode and Effects analysis (DMEA).. higher level mode and Effects analysis (FMEA).. indenture indenture Failure L_5ivM-IL-STD-1629 ACONTENTS (Continued) rules and systemFailure definitiin'..Coordination of effoit'..General specifications and development study data and critical item I and Category II Failure mode Failure points MODE AND Effects MODE AND Effects MODE, Effects , AND CRITICALITY ANALYSIS of a functional block of a reliability block of FMEA worksheet of CA worksheet format.

6 102-6 Example of criticality matrix..102-7 of damage mode and Effects analysis format t104-5 APPENDIX AND TAILORING GUIDE .. DOCUMENTS (not applicable) .. (not applicable) .. item descriptions (DID).. (Continued)PageExample of FMECA-maintainability informationworksheet format .. ' of of (task 101)CA (task 102) 1A-3 FMECA-maintainability"i~for~ation'(task* 103)..A-3A-4 DMEA (task 104)..A-4 Criticality number (C,) calculation standard establishes requirements and proceduresfor a Failure mode, Effects ,and criticality analysis (FMECA)

7 To systematically evaluate and document,by item Failure mode analysis,the potential impact of each functional or hardware Failure on missionsuccess, personnel and system safety, system performance, maintainability,and maintenance potential Failure is ranked by theseverity of its effect in order that appropriate corrective actions maybe taken to eliminate or control the high risk standard applies to the acquisition ofall designated DoD systems and primarily applies activity phases of demonstration and validation and full-scaleengineering development; , design, research and development, andtest and standard also can be used during productionand deployment to analyze the final hardware design or any major FMRCA tasks contained in this standard apply to all items standard does not apply to A containsadditional application and tailoring tasks are numbered sequentially asthey are introduced into this standard with the first task being general revision of this standard whichresults in a revision of sections 1,2, 3, or 4 will be indicated byrevision letter after this standard number.

8 Together with date of revisions of FMECA tasks are indicated by aletter following the task. For example,for task 101, the first revisionis 101A, the second revision is the basic document isrevised,those requirements not affected by change retain their of tasks contained herein shall bereferenced by standard number(s). data as called for in individual of following documents of theissue in effect on the date of invitation for bid or request for proposal,are referenced in this standard for information and , Technical; Functionally Oriented Maintenancs_Manuals for Systems and EquipmentDefinitions of Item Levels, Item Exchangeability,Models and Related TermsMaintainability Program Requirements (forSystems and Equipment)Definitions of Effectiveness Terms for Reliability,Maintainability, Human Factors and SafetyReliability PredictionWork Unit Codes for Aeronautical Equipment.

9 Uniform Numbering SystemReliability Program for Systems and EquipmentDevelopment and ProductionSystem Safety Program RequirementsLogistics Support Analysis8n Aircraft,Fault Diagnosis, Subsystems,Analysis/Synthesis ofSurvivability, Aircraft; Establishment andConduct of Programs forMaintenance Plan Analysis for Aircraft andGround Support EquipmentsReliability Prediction of Electronic Equipment(Copies of specifications, standards, drawings, and publicalionsrequired by contractors in connection with specific procurement functionsshould be obtained from the procuring activity or as directed by thecontracting officer.)

10 Definitions of termsaccordance with the'definitions in MIL-STD-280,721, MIL-STD-780, MIL-STD-785, MIL-STD-882, andexception and addition of the following:used herein are inMIL-STD-470, MlL-STD-MIL-STD-1388, with private sector enterprise engaged toprovide services or products within agreed limits specified by a used in this standard, the term "contractor" includesgovernment operated activities developing or producing military systemsand documented design, process, procedure,or materials change implemented and validated to correct the cause offailure or design that are available orcan be taken by an operator to negate or mitigate the effect of a failureon a relative measure of the consequences of afailure mode and its frequency of analysis (CA).