精益生产的基础

LeanManufacturingBasicsAzaBadurdeenLeanManufacturingBasics1LeanManufacturingBasicsByAzaBadurdeenCopyright©2007Thisbookisfreelydistributedthorough=://://(WIP)25Transportation25Inappropriateprocessing26Excessmotionorergonomicproblems27Defectedproducts28Underutilizationofemployees29Canallofthesewastesbeavoided30Leanmanufacturingtools33JustInTime(JIT)38JITpurchasing39JITProduction39JITdistribution39Workcells42Kanbantooling43Withdrawalkanban43(TPM)47Preventivemaintenance48Correctivemaintenance48Maintenanceprevention48SingleMinuteDieExchange(SMDE)49LeanManufacturingtoLeanEnterprise50Advantagesofleanmanufacturing52Whyleanissosuccessful55Leanmanufacturingfortoday’sworld60’thadmuchofcapitaltoworkwith.Thereforecapitalwasveryimportant.WiththeseconstrainsTaiichiOhnotookoverthechallengeofachievingtheimpossible.WithhisrighthandmanDr.SheigoShingofornextthreedecadeshebuilttheToyotaproductionsystemortheJustInTimesystem.AlthoughtheconceptwasmasteredinJapanfortheToyotaproductionsystem,therootsofthisconceptgoesintothesixteenthcentury.EliWhitney’sconceptofinterchangeablepartssaidtobetheveryinitialbeginningofthisconcept.ButfirstoratleastfamousimplementationofsomethingsimilartoJIThappenedacenturylaterinmanufacturingofFordModelT(in1910)automobiledesign.Manufacturingwasbasedonlineassembly.Everypart’sinabilitytothechange.ThiswasduetothepushstrategyimplementedintheFordssystem.Theyreliedonkeepingmachinebusywithoutthinkingaboutthefinaloutcome.TheyhadhugestocksintheformoffinishedgoodsandintheformofWorkInProgress.Thisledtotheinflexibilityofthesystem.Alsothiswastedmoneyunnoticed.Anothermajordrawbackofthesystemwasthepoorhandlingofthehumanresource.Thisledtohavealessmotivatedsetofpeopleintheorganization.ButinJapan,theystudiedthesystemverywellandsawtheproblemsthatFordsystemhad.ButthecoreconceptoftheFordsystemwasobeyed.Thisisthecontinuousflowofvaluesystem.Anythingdistractingittreatedasawaste.VariouspioneeredworkfrompeoplelikeDemingandJuraninthefieldofqualityimprovementwasusedinthesystem.Thisboughtbuiltinqualitytothesystem.MoreimportantlyOhnoandShingounderstoodthedrawbacksinthepushsystemandunderstoodtheroleplayedbytheinventory.Thisledto(thatiswhenpeoplebuytheproduct),theyarerefilledwithnewones.ThissystemdevelopedinToyotafrom1949to1975virtuallyunnoticedbytheothersevenwithinJapan.Butintheoilcrisisin1973Japaneconomysufferedandmosto