Application-of-Concurrent-Engineering-in-New-Autom

ApplicationofConcurrentEngineeringinNewAutomobileDesignSubrataMitraandBaniKSinhaOperationsManagementGroup,IndianInstituteofManagementCalcutta,[e-mail],[e-mail]neering(CE)hasgainedimportanceworldwideinthelightofincreasedcompetitionandglobalisation.CEprovidesacompetitiveadvantagetocompaniesbyhelpingthemreducetheproductdevelopmentcycleandquicklybringproductstomarket.Inthispaper,applicationofCEindesignofnewautomobilesisdemonstratedwithanexample.Aclusteringalgorithm,calledBondEnergyAlgorithm(BEA),isappliedtoidentifydesignactivities,whichcanbeperformedsimultaneously.1.IntroductionApplicationofConcurrentEngineering(CE)principlesinmanufacturingandconstructionindustriesworldwidehasgainedimportanceinthelightofincreasedcompetitionandglobalisation.Inthecontextofmanufacturingindustries,CEhelpscompaniesshortentheproductdevelopmentcycleandquicklybringproductstomarket.CEisamulti-disciplinaryapproach,anditisconcernedwithallelementsoftheproductlifecyclefromconceptionthroughdisposal.CEalsohelpsinachievinghigherqualityoftheproductandhigherproductivity[5].Inautomobiles,approximately80%oftheoverallproductmanufacturing/assemblycostiscommittedattheendofthedesignprocess.ThisindicatesthatautomotivedesignandassemblysystemmodellingatanearlystageoftheCEprocessisimportant[1].TheJapaneseautomobilecompanieshavesuccessfullyimplementedCEprinciples.WhiletheaveragetimetakenfromfirstdesigntocustomerdeliverybyU.S.andEuropeanautomakersis60months,Japanesecompaniesrolloutanewcarin40months,asavingofone-thirdindevelopmenttime[2].Japaneseindustryneedsonlyabout60%ofthetimeandhalfthepeopletodevelopacarascomparedtoEuropeanIndustry[4].Inthispaper,theapplicationofCEindesignofnewautomobilesisdemonstratedwiththehelpofanexample.Thedesignparametersareidentified,andaclusteringalgorithm,calledBondEnergyAlgorithm(BEA),isappliedtospecifydesignactivities,whichcanbeperformedsimultaneously.Finally,discussionsbasedontheresultsofapplicationofthealgorithmarepresented.2.DesignParametersinAutomobilesItiscustomarytodecomposeanyprojectintoanumberofsub-systems(SS)basedonfunctionalrequirements.Eachsub-systemcanbefurthersubdividedintoanumberofmanageableandhomogenousunitscalledmodules(M).Eachmodule,inturn,canbefurthersubdividedintoanumberofdesignfactors(DF).Weconsiderthreecriticalsub-systemsinautomobiledesign,namelyPowerTrainEngineering,BodyEngineering,andPaintShopDesignandOperations.Thesub-systemsarefurtherbrokendownintomodulesanddesignissues,whichareshowninatwo-columnformat.1.PowerTrainEngineering(SS1)•Enginedesign(M1)PowerandfuelspecificationsEnginedesign,prototypeandtestingPlant&machineryandconstructionPlantservices•GearBoxdesign(M2)EnginespecificationsGearBoxdesign,prototypeandtestingPlant&machineryandconstructionPlantservices•Assemblyandtesting(M3)PowertrainspecificationsPlantandmachineryPlantservices2.BodyEngineering(SS2)•Bodydesign(M4)PrototypedesignBodyspecificationsBlockdesignandassemblydesign•Diedesign(M5)PanelspecificationsDiedesignInstallation&commissioningPlantservices•Welddesign(M6)WeldprocessplanningPlant&machineryandconstructionPlantservices3.PaintShopDesignandOperations(SS3)(M7)PaintspecificationsPaintprocessplanningPlant&machineryandconstructionPlantservicesThedesignfactorsrelevanttothemodulesareasfollows.1.Powerandfuelspecifications2.Enginedesign3.GearBoxdesign4.Bodyspecifications5.Blockdesignandassemblydesign6.Diedesign7.Weldprocessplanning8.Paintspecifications9.Paintprocessplanning10.Assemblyandtestingplant&machinery11.Assemblyandtestingplantservices12.EngineandGearBoxshopplant&machinery13.EngineandGearBoxshopplantservices14.EngineandGearBoxshopconstruction15.Dieshopinstallationandcommissioning16.Dieshopplantservices17.Weldshopplant&machinery18.Weldshopplantservices19.Weldshopconstruction20.Paintshopplant&machinery21.Paintshopconstruction22.Paintshopplantservices3.ApplicationofConcurrentEngineeringApplicationofCErequiresidentificationofmodules,whichsharecommondesignfactors.Anincidencematrixistobeconstructedwithrowsrepresentingmodulesandcolumnsdesignfactors.Anelementofthematrix,aij,isassignedthevalue1(0)ifdesignfactorjis(isnot)anessentialrequirementformodulei.Theassignmentofbinarynumbersposesachallengetothedesignerrequiringjudgementandexperiencetobeexercised.Aclusteringalgorithm,calledBondEnergyAlgorithm(BEA),issubsequentlyemployedtoobtaintheindependentclustersofmodulesanddesignfactors.Thealgorithmisdiscussedbelow.3.1.BondEnergyAlgorithm(BEA)BEAhaswideapplicationsinGroupTechnology,ManufacturingCellFormationandRelationalDatabaseManagementSystems.Thepurposeofthealgorithmistodisplaythenaturalvariablegroupsandtheirinterrelationsbypermutingtherowsandcolumnsofaninputmatrix[3].BEAseekstomaximisetheMeasureofEffectiveness(ME),ameasureofthedensityofbondsbetweenneighbouringelementsoftheinputmatrix.Foramatrixwithmrowsandncolumns,theMEisgivenby[]MEaaaaaijjnijijijijim=+++=+-+-=∑∑12111111withaaaaojmjiin====++1010TheflowchartofthealgorithmisshowninFigure1.YesNoFigure1.FlowchartoftheBondEnergyAlgorit