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5th International Quality ConferenceMay 20th 2011Center for Quality, Faculty of Mechanical Engineering, University of Kragujevac

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Dobrivoje ati1)

Slavko Arsovski 1)

Branislav Jeremi1)

Jasna Gliovi1)

1) Faculty of MechanicalEngineering, University ofKragujevac, Serbia, Sestre

Janjic 6, 34 000 Kraguejvac,Serbia

FMEA IN PRODUCT DEVELOPMENT PHASE

Abstract: In the first part of paper, next to the descriptionmethod of Failure Modes and Effects Analysis - FMEA, thehistory of the development and application of methods withspecial emphasis on the use of FMEA in the automotiveindustry is given. FMEA can be applied at all stages of thelife cycle of one technical system. However, itseffectiveness is the largest, if applied at productdevelopment phase by a team of experts from variouscompany's functions. Therefore, conceptual, design andprocess FMEA is discussed in this paper. A detaileddescription of the relations between these methods and theorder of application is considered. Based on FMEAworking plan it was formed the algorithm procedure ofapplication of design FMEA method. The specific steps ofFMEA procedure starting from the formation of FMEAteam until documenting of the analysis is explained.Keywords: FMEA, product development, types of FMEA,design FMEA, methodology.

1. INTRODUCTION

Failure Modes and Effects Analysis(FMEA) is one of the basic and the mostused method for analyzing the safety andreliability of technical systems [1]. FMEAis basically an inductive method. It isbased on consideration of all potentialfailures of the systems components andtheir effects on the system. Efficiency ofFMEA method application is the greatest ifused in the phase of design of mechanicalsystems by multi-disciplinary team ofexperts. Based on the obtained results ofanalysis, potential failure causes of systemelements are eliminated or reduced to thesmallest possible measure at the start.FMEA may be defined as a systematicgroup of activities intended to [2, 3, 4]:recognize and evaluate the potential failureof a product/process and the effects of thatfailure, identify action that could eliminateor reduce the chance of potential failureoccurring and document the entire process.

The FMEA was developed for theU.S. military purposes as a technique forassessment of reliability throughdetermination of effects of different failuremodes of technical systems [5]. Failureswere classified according to their impacton mission success andpersonnel/equipment safety. This methoddates from November 9th, 1949, as anofficial document in a form of anAmerican military standard, denoted asMIL-P 1629 [6], titled Procedures forPerforming a Failure Mode, Effects andCriticality Analysis.

Outside the military, FMEA began tobe used in the aircraft and space industry.During the fifties and sixties, airlinecompany Boeing has developed FMEAmethod and became one of its creators.The primary push came during the 1960s,while developing the means to put a manon the moon and return him safely to earth[4]. NASA in 1966 had published itsprocedure for FMEA, which was used inthe Apollo program [7].

680 D. ati, S. Arsovski, B. Jeremi, J. Gliovi

Although FMEA is considered anuseful tool for improving product quality,this method is beginning to be used in theautomotive industry only in the earlyseventies. In 1971 Ford Motor Companyintroduces an internal standard that refersto the FMEA method [8]. In the early1980s, United States automotivecompanies began to formally incorporateFMEA into their product developmentprocess. A task force representing ChryslerCorporation, Ford Motor Company andGeneral Motors Corporation developed QS9000 standard in an effort to standardizesupplier quality systems. QS 9000 is theautomotive analogy to better knownstandard ISO 9000. The AutomotiveIndustry Action Group (AIAG) and theAmerican Society for Quality Control(ASQC) copyrighted industry wide FMEAManuel in February of 1993 [9]. In 1994,the Society of Automotive Engineers(SAE) published SAE J-1739, PotentialFailure Mode and Effects Analysis InDesign (Design FMEA) and PotentialFailure Mode and Effects Analysis InManufacturing and Assembly Proce-sses(Process FMEA Reference Manual) [10],which is based on the Ford's manual in1988 [11].

Some of the first European standardsthat describe the application of FMEA inthe automotive industry were 4.2 VDAVerband der Automobil-industrie - VDA1986, "Guidelines to FMEA" Bri-tishSociety of Motor Manufacturers andTraders - SMMT in 1987, internalstandards of BMW, Renault in 1987,Volkswagen in 1988, etc. [8].

In 1999 the joint work of InternationalAutomotive Task Force - IATF, consistingof leading U.S. and European carmanufacturers and national tradeorganizations, Japan AutomobileManufacturers Association - JAMA and aTechnical Committee - TC InternationalOrganization for Standardization ISO / TC176, it was established the standard -Technical Specification - TS ISO / TS

16949 for the car and spare partsmanufacturers [12].

2. TYPES OF FMEA IN THEDEVELOPMENT STAGE

From the standpoint of the object ofanalysis in the product development phase,there are three types of FMEA method [2]:conceptual, design and process FMEA.The same methodology and form fordocumenting the proceedings, for all threetypes of FMEA method, is used. Mutualdifferences are in the object of analysis,the time of implementation, the function ofthe company that is the holder of activities,etc.

Conceptual or system FMEA is thehighest level. This type of FMEA is usedto detect and prevent failures of systemand sub-systems in the early stages ofdesigning the project. Based on thecompleted concept, the interaction ofsubsystem and components within thecomplex system is considered. ConceptualFMEA is used to confirm that thespecification of the designed systemsreduces the risk of failure during thedesign.

Design FMEA is used as an aid toidentification and prevention of failureswhose causes are directly related to thedesign of products. The basis for theimplementation of the project FMEA iscompleted design documentation.

Process FMEA is used to identify thecauses of potential failure modes that mayoccur during manufacture or assemblingparts or assemblies and to define measuresto eliminate identified defects. The basisfor this method is completed technologicaldocumentation.

A methodological connection amongthe above procedures FMEA in productdevelopment phase is shown in Figure 1.The figure is obtained by generalizingmethodological connections of differenttypes of FMEA in the development phaseof an ignition distributors of an internal

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combustion engine shown in this paper[13]. According to the figure, processFMEA is based on the results of design

FMEA, and it based on the results ofconceptual FMEA.

Types ofFMEA

ConceptualFMEADesignFMEAProcessFMEA

Function FailureeffectsFailuremode

Cause offailure

Failure ofthe system

Failure of thecomponent

Processfault

Cause ofprocess fault

Influence on userand environment

Failure of thecomponent

Failure of thesystem

ProductProcess

Failure of thecomponentProcess

fault

Function ofcomponent

Processfunction

Functionof system

Componentname

Processname

Systemname

Fig. 1 Methodological connection between different types of FMEA in productdevelopment phase

The cause - effect chain in Figure 1represents a hierarchical ladder system'sactivity: the production process, from thecomponents to the system, i.e. from thecauses of failure to failure modes, from thefailure modes to its effects, and all that isfollowed by FMEA method.

Figure 1 shows also the sequence ofdifferent types of FMEA in productdevelopment phase. By the analysis ofoperation modes of the system it can bereached potential failure modes that resultin total or partial failure of the objectivefunction of the system. By detailedanalysis of each individual system failure,the causes and effects of those failures canbe identified. The causes of system failuresare actually failures of its components. Theanalysis of the failure's causes ofcomponents leads to identification ofdefects in the production process thatcause them.

Between the conceptual, design andprocess FMEA strictly separation must becarried out. Transition between theseconcepts is gradual. It should be borne inmind that only after the determination ofthe manufacture procedure may estimaterisk factors of design FMEA. However, theseparation between different types ofFMEA is done for reasons of reducing the

complexity of the task.Time coordination of implementation

of FMEA methods with other developmentactivities represents one of the crucialfactors for the success of the project. Likeother developmental processes, FMEA iscarried out before the start of production,perfectly respecting the time demands.

In order to FMEA become successful,it must be finished before the realization ofproducts or processes. Timesynchronization of implementation ofdifferent types of FMEA in productdevelopment phase enables automatictaking into account the results of previousFMEA and feedback data on changes inprojects of products or processes, thusreducing the need for subsequent changesand significantly reduces time and costs ofdevelopment. The phases ofimplementation of different types ofFMEA as a function of the individualphases of the product life cycle is given inTable 1 [2].

Since the FMEA is a "living"document, the term completion marks theend of the first iterative circle of FMEAand directing obtained results to the FMEAentrance of the next circle to correct. Startof implementation of project and processFMEA is a phase-shifted for the time

682 D. ati, S. Arsovski, B. Jeremi, J. Gliovi

required for obtaining necessaryinformation from conceptual FMEA.

Product developmenttiming Conceptual FMEA Design FMEA Process FMEA

Design concept InitiateDesign simulation Complete Initiate InitiateDetailed design UpdatePrototype test Complete UpdateProduct launch CompleteField usage Update Update Update

Table 1 - FMEA timing in the product development cycle

FMEA should be updated as theproject development progresses. Allchanges in design of products or processesand changes of the initial specificationsmust be properly reviewed and accompanythrough the process of FMEA. Properlyapplied FMEA is an interactive iterativeprocess that never ends. FMEA is a type ofdocument that is constantly adapting tochanges that occur in the productdevelopment process.

3. PROCEDURE FOR DESIGNFMEA

Systematic of design failure modesand effects analysis in the productdevelopment phase is ensured by FMEAoperation plan [13], which is the base forformulation of the flowchart of theprocedure for application of project FMEAmethod, presented in Fig. 2 [14].According to the presented flowchart,application of design FMEA method goesthrough the following phases:

1. Creating of FMEA team.Organisation of work on FMEA andappointment of responsible person (leader)for FMEA team creation in the companyare defined by corresponding instruction.For construction FMEA, FMEA teamleader comes from product designdepartment and for process FMEA, FMEAteam leader comes from technology design

department. Selection of other teammembers is done by agreement betweenthe person responsible for creation of theFMEA team and the heads of the technicaldepartments from which team membersare appointed.

2. Work plan and preparation froanalysis are of the outmost importance forsuccessful conduction of the FMEAprocedure. In the preparation phase, theteam leader acquaints the FMEA teammembers with the structure of the observedsystem and its operation modes usingcorresponding documents (designassignment, basic data on product and itsstructure, technical conditions, designdocumentation and other). After havingbeen acquainted with the object of theanalysis, each team member, in his furtherwork, prepares relevant documentation andinformation on the subject of the analysisfrom the area that his functional unitcovers in the company. Based on gatheredinformation, each team member reacheshis own conclusions.

3. Analysis of potential failures. Bysystematic analysis of the operation modesand functional parameters of individualcomponents of the system, all possibleinfluences on system operation, possiblecauses and effects of the systemcomponent's failure are detected.Identification of potential failure modesmay be conducted by application of FaultTree Analysis - FTA or by using Ishikawachart. For the purpose of assessment of

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failure risk, it is necessary to recordscheduled control measures for failure

cause detection in this phase.

Fig. 2 - Flowchart of the procedure for application of design FMEA method

684 D. ati, S. Arsovski, B. Jeremi, J. Gliovi

4. Project assessment. Teamevaluation of occurrence rating of thefailure mode, O, severity rating of failureeffects (weighting factor), S, and detectionrating for a potential failure mode, D, andcalculation of risk priority number, RPN,as their product, is conducted in the projectassessment phase, based on acquired dataon every cause-failure couple. By rankingof calculated values for risk prioritynumber and by adoption of criteria forfailure acuteness, a basis for dispatchingpriority for conducting measures forquality improvement is made.

5. Work on quality improvement. Forevery critical failure mode,preventive/corrective measures areproposed in order to reduce some or allrisk factor values. Persons responsible forconduction of these measures are selectedand deadlines for their execution are set.Invention of quality improvementmeasures should be obtained inmultidisciplinary working groups, withapplication of corresponding creativitytechniques.

6. Assessment of preventive/corrective measures effects. After qualityimprovement measures are introduced, theFMEA team has a task to establish theeffects of their application, by assessmentof new risk factors values using thesame assessment criteria. FMEA analysisconcludes if adopted acuteness criteria aremet, both for individual risk factor valuesand for total risk. If, even afterintroduction of quality improvementmeasures, the risk factor values are largerthan adopted limit values, new measuresare defined and conducted until theassessment values are satisfactory.

7. FMEA documentation. A blankform is used for FMEA documentation andit is fulfilled parallel with conduction ofindividual phases of the procedure. Everychange in the project must be followed byFMEA documentation change. The form

for the design FMEA is not univerzal. It isnot standradized [15]. Each company hasits own form that reflects the needs of theorganization and the concerns of thecustomer. In the automotive industry,however, efforts have ben successful andon July 1. 1993 a standardized form andprocedure was published by AIAG [9].

4. CONCLUSIONS

Application of FMEA method in thephase of development of mechanicalsystems enables scientific foundation ofproblem solving consisting of: detectionand identification of potential failuremodes and defects, determination of theircauses, creation of the base for suggestionof preventive/corrective measures forovercoming the problem and definition ofquantitative indices that confirm thesuccess of application of adoptedmeasures. Determination of criticalelements of mechanical systems that limitreliable and safe operation of the systemand taking of preventive measures in orderto reduce the acuteness present the fastestand the cheapest way to increase reliabilityand, accordingly, the product's quality.

Use value of FMEA results is inproportion to volume and credibility of theinitial data. This points to need that everycompany should form information systemfor acquisition and processing of data onerrors, defects and failures of company'sproducts. Organised system for dataacquisition must provide continuous flowof data, their processing and availability.In order to get complex and credibledatabase on modes, causes, effects andoperation periods before failure ofmechanical systems or elements occurs,data must be acquired in the design phase,development phase and in product'sexploitation.

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REFERENCES:

[1] International Standard IEC 60812, Analysis techniques for system reliability - Procedurefor failure mode and effects analysis (FMEA), Second ed., International Electro-mechanical Commission , 2006, Geneva.

[2] Lazor D J.: Failure Mode and Effects Analysis (FMEA) and Fault Tree Analysis (FTA)(Success Tree Analysis - STA), Handbook of Reliability Engineering and Management,1995, McGraw-Hill, New York, p. 6.1-6.46.

[3] Failure Mode and Effects Analysis, FMEA Handbook Version 4.1, Ford Motor Company,Dearborn, MI, 2004.

[4] Advantages of Implementing FMEA in Auto-motive Industry, from http://adex.com.my/Document/ FMEA IN AUTOMOTIVE.pdf, 6th May 2010, accessed on 2010-10-22.

[5] Failure Mode and Effects Analysis, Chapter13 in: Hazard Analysis Techniques for SystemSafety, by Ericson C.A., II, 2005, John Wiley & Sons, Inc.

[6] MIL-P-1629, Procedure for Performing a Failure Mode Effect and Criticality Analysis,United States Military Procedure, November 9, 1949.

[7] Procedure for Failure Mode, Effects and Criticality Analysis (FMECA), NationalAeronautics and Space Administration. 1966. RA0060131A.http://hdl.handle.net/2060/ 19700076494. Retrieved 2010-03-13

[8] Eilers J.: APIS IQ-Software (Entwurf), 24. November 2008.[9] AIAG, FMEA-3 Potential Failure Mode and Effects Analysis, 2rd ed., Automotive

Industry Action Group (AIAG), 2002.[10] SAE Standard J-1739, Potential Failure Mode and Effects Analysis in Design (Design

FMEA) and Potential Failure Mode and Effects Analysis in Manufacturing and AssemblyProcesses (Process FMEA) and Effects Analysis for Machinery (Machinery FMEA),2002.

[11] Potential Failure Mode and Effects Analysis in Design (Design FMEA) and forManufacturing and Assembly Process (Process FMEA) Instruction Manual, Ford MotorCompany, 1988, Detroit, MI.

[12] McDermott R.E., Mikulak R.J. and Beauregard M.R.: The Basics of FMEA, 2nd ed., 2009,Taylor & Francis Group.

[13] Kersten V.G.: FMEA - Eine wirksame methode zur pravention qualitatssicherung, VDI-1132, Nr. 10, 1990., p. 201-207.

[14] ati D.: Reliability in the Development of Mechanical Systems Faculty of MechanicalEngineering, 2010, Kragujevac.

[15] Stamatis D.H.: Failure mode and effect analysis, 2nd ed., American Society for Quality,Milwaukee, 2003, Wisconsin.

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