工厂化生产住宅

ProductionProcessforManufacturedHousingO.Senghore1;M.Hastak2;T.S.Abdelhamid3;A.AbuHammad4;andM.G.Syal5Abstract:Amanufacturedhomeiscompletelybuiltinacontrolledfactoryenvironment.Despitealargeshareofthemarket,themanufacturedhousingindustryhasalongwaytogotowardsstreamliningitsproductionprocess.Theobjectiveofthispaperistomaptheproductionprocessofamanufacturedhousingfactoryandtodemonstrateviasimulationhowtheprocesscanbeimproved.Theproduc-tionprocessincludingassembly,feeder,andstoragestationsweremappedusingdatafromseveralmanufacturedhousingplantsandin-depthcasestudiesattwoplantsinnorthernIndiana.Thecasestudyplantswerealsousedforcollectingcycle-timedatafordevelopingthesimulationmodelfortheroofingprocess.Subsequently,four“whatif”scenarioswereconductedtoillustratepotentialimprovementstotheproductionprocess.Theeffortspresentedinthispaperarepartofon-goingresearchsponsoredbytheNationalScienceFoundationunderthePartnershipforAdvancementofTechnologyinHousing(PATH)initiative.DOI:10.1061/(ASCE)0733-9364(2004)130:5(708)CEDatabasesubjectheadings:Manufacturedhomes;Productionplanning;Productionengineering;Simulation;Simulationmodels.IntroductionTheUnitedStatesCensusBureauhasestimatedthatHousingandUrbanDevelopment(HUD)code-basedmanufacturedhomesrep-resented22.7%ofallnewsingle-familyhousingin1998[MHIQuickfacts1999–2000(MHI2000)].TheHUDcodemanufac-turedhousinghasbeenevolvingsince1976andgoesevenfurtherbackintheearlypartofthe20thcenturywhentheywerecalledtrailers(HUD1998).Over19millionpeopleacrossthecountryhavedecidedtomakeamanufacturedhometheirwayoflife(MMHA2000).Thetrends,assummarizedinTable1,clearlyshowthatmanufacturedhousinghasbecomeaviableoptiontohomebuyersinAmerica.Amanufacturedhomeisbuiltinacontrolledfactoryenviron-mentonapermanentchassisthatisdesignedtobeusedwithorwithoutapermanentfoundationwhenconnectedtotherequiredutilities.ManufacturedhomesarebuilttothefederalManufac-turedHomeConstructionSafetyStandardsenforcedbytheDe-partmentofHousingandUrbanDevelopment(HUD1995).Manufacturedhomesaresinglestoryandaredeliveredtothehomesite,whichcouldbeaprivatepropertyorinamanufacturedhomecommunity,inone,two,oroccasionally,threesections.Despiteagrowingmarket,themanufacturedhousingindustryhasnotbeenabletoemergeasatechnologicallyadvancedindus-try(Mehrotraetal.2002).Atypicalmanufacturedhousingplantfailstoproduceatmaximumcapacityandproductionratebecauseofseveralconstraintsintheproductionprocesssuchas:1.Laborintensiveratherthantechnologybasedproductionpro-cess;2.Thelackofextensiverepetitioninthemanufacturedhousingproductionprocess.Eachhousingunitgoingthroughtheas-semblyprocessisunique;and3.Duetothedifferencebetweensite-builtandfactory-builthousingprocesses,innovationsinsite-builthousingarenotdirectlyapplicabletomanufacturedhousing.Inordertodevelopaneffectiveandefficientproductionsys-temthatwouldoptimizethelabor,technology,andmaterialutili-zation,itisimportanttoidentifythedeficienciesinthecurrentproductionprocessesusedbythemanufacturedhousingindustryandtosuggestinnovativemethodsforimprovingtheproductionprocess.Theobjectiveofthispaperistoillustratetheproductionpro-cessofamanufacturedhousingfactoryandtodemonstrateviasimulationhowtheproductionprocessaswellasthelaborandmaterialutilizationcouldbeimprovedandstreamlined.There-sultspresentedinthispaperarepartofongoingresearchspon-soredbytheNationalScienceFoundationunderthePartnershipforAdvancementofTechnologyinHousing(PATH)initiative.ManufacturedHousingProductionProcessTheconstructionprocessofamanufacturedhousingunitissimi-larinmanywaystothatofasite-builthousingunit.Whilethematerialsusedinbothproductionprocessesaresimilar,theenvi-1Formerly,GraduateStudent,ConstructionManagementProgram,MichiganStateUniv.,EastLansing,MI48824.E-mail:[e-mail]2AssociateProfessor,DivisionofConstructionEngineering&Man-agement,SchoolofCivilEngineering,PurdueUniv.,WestLafayette,IN47907.E-mail:[e-mail]3AssistantProfessor,ConstructionManagementProgram,MichiganStateUniv.,EastLansing,MI48824.E-mail:[e-mail]4PhDStudent,Dept.ofCivil&EnvironmentalEngineering,Univ.ofCincinnati,Cincinnati,OH45221.E-mail:[e-mail]5Professor,ConstructionManagementProgram,andDirector,HousingandInfrastructureInitiative,203FarrallHall,MichiganStateUniv.,EastLansing,MI48824(correspondingauthor).E-mail:[e-mail]1,2005.Separatediscussionsmustbesubmittedforindividualpapers.Toextendtheclosingdatebyonemonth,awrittenrequestmustbefiledwiththeASCEManagingEditor.ThemanuscriptforthispaperwassubmittedforreviewandpossiblepublicationonFebruary3,2003;approvedonMay14,2003.ThispaperispartoftheJournalofConstructionEngineeringandManagement,Vol.130,No.5,October1,2004.©ASCE,ISSN0733-9364/2004/5-708–718/$18.00.708/JOURNALOFCONSTRUCTIONENGINEERINGANDMANAGEMENT©ASCE/SEPTEMBER/OCTOBER2004ronmentinwhichtheyarebuiltisquitedifferent(refertoFigs.1and2).TwomanufacturedhousingplantsinnorthernIndianawereusedascasestudiestomaptheproductionprocesswithrespecttothesequenceofactivitiesateachstation(includingthefeederstations),dur