质量管理第7讲 森口体系

2019/8/231质量管理第三章质量控制与质量改进第三节森口体系南京工程学院经济管理学院高峰2019/8/232森口体系的涵义森口体系，更确切地说，是一种生产管理思想，是以丰田准时生产制的合作开发者森口凡一的名字命名的，它与基于统计的质量控制方法相类似，不过在许多方面还存在冲突。2019/8/233检验方法2019/8/234森口体系的检验方法1．判断式检验指把次品从合格品中挑出来．将有关信息立即反馈到生产该产品的工人那里，然后由该工人进行修理．这种方法有时也叫“质检”。森口认同大家的观点，认为质检不是有效的质量管理方法，应慎用。2．信息式检验运用检验中得来的数据控制生产流程，防止次品出现。森口担心，传统的统计式质量管理不能在生产之后即时检查，因此不能提供最好的信息来确定质量问题的起因并用于将来的防错。3．溯源式检验在事件发生之前就确认好是否存在进行高质量生产所必需的条件。这就需要在生产之前检查员工的操作条件，而非在生产之后再检查。森口认为，溯源式检验是一种理想的质控手段，因为在生产流程开始运作之前就能获得有关反馈。2019/8/235SMED2019/8/236森口数分钟更换模具方式森口指出，设备调试分内部调试和外部调试两大部分，内部调试必须关机进行，而外部调试则可在机器运行中操作。如果将大家都认为只能通过内部调试进行的各种程序变为外部调试，就能够大大提高运作效率。2019/8/237SingleMinuteExchangeofDie(SMED)Setupreduction(oftenknownasSingleMinuteExchangeofDieorSMED)isoneofthemoremundaneaspectsofLeanManufacturingandisoftenignored.2019/8/238Risk&DifficultyLoopWhenwerunlargelotsofeachproduct,setupsonthatproductareinfrequent.Setupstakeskill,practiceandcoaching,muchlikegolf.Whenoperatorsperformsetupsinfrequentlytheydonotlearnthemwell.Thisleadstotheperceptionthatsetupsaredifficultandrisky.(Youneverknowhowlongitwilltakeorwhethertheproductwillberight).Theperceptionsofriskanddifficultyencourageslargelotsandthusfewersetups.2019/8/239PieceCostLoopWithlargelots,afixedsetupcostisamortizedoveralargenumberofunits.Thisseemstoreducetheunitcost.Thereareoffsettingcostsassociatedwiththeresultinginventories,buttheseoffsettingcostsareusuallyburiedintheoverhead.Thisalsoencourageslargelotsorruns.2019/8/2310ResultsTheconsequenceishighinventoryandcomplexscheduling.Thesegiverisetoaplethoracostsandnegativeconsequences.Theblackholeofoverheadsucksinmostofthecosts.Otherpenaltiessuchaserraticdeliveriesarefarremovedfromthefundamentalcauseanditisdifficulttolinkcauseandeffect.Limitingmechanismspreventlotsizesfromgoingtoinfinitybuttheseareoftenweak.2019/8/2311Theleveragepointinthissystemisintheriskperceptionloop.Ifwecanmakesetupsfast,easyandpredictabletheloopreversesintoavirtuouscycle.Easysetupsencouragesmalllotsandsmalllotsmeanmoresetupswhichincreasesconfidenceandsetupskill.Inaddition,thepiececostloopbecomesveryweak.Asaresult,inventorycomesdownandschedulingiseasier,TheflowofcostsintotheBlackHoleslowsaspeoplespendlesstimeexpediting,searchingandchasing.2019/8/2312HowToReduceSetupTimeSetupreductionshouldbeapproachedinfourphasesorstagesasillustratedbelow.Isisusuallybesttorepeattheprocessthroughseveraliterationsspacedseveralmonthsapart.2019/8/2313HowToReduceSetupTime2019/8/23141.Maintenance,OrganizationandHousekeepingItoftenhappensthatsetupproblemsarerelatedtopoormaintenancesuchaswornparts,worntooling,dirt,ordamagedthreads.Disorganizationandpoorhousekeepingarealsocontributorstosetupproblems.Theseareeasytofixandshouldbeafirststep.2019/8/23152.InternalElementstoExternalInternalelementsoccurwhenthemachineisdown.Examineeachinternalelementandseeifitcannotbedoneexternally.Forexample,thepre-heatingofaninjectionmoldingdiecouldbedonebeforeitgoesintothemachine.2019/8/23163.ImproveElementsHereweexamineeveryelementtoseehowwecaneliminateit,simplifyit,reducethetimerequiredorimproveitinsomeotherway.2019/8/23174.EliminateAdjustmentsAdjustmentsareoftenthemosttimeconsuming,frustratinganderrorpronepartsofasetup.Therearemanywaystoeliminatethementirelyandthisistheultimategoal.2019/8/2318SetupReduction-TypicalResultsSetupreduction(SMED)techniquesapplyacrossmanyindustriesandprocesstechnologies.Thelistbelowshowssomeexamples.2019/8/2319IndustryEquipmentBeforeAfter%AssemblyAdhesiveApplicator12:09:000:21:0097%AssemblyAirCleanerAssembly2:00:000:00:00100%CosmeticsCapperMachine0:09:360:03:2165%ElectronicsPCBInserion-ICs0:13:300:05:5656%ElectronicsPCBInsertion-Axial0:05:180:04:1819%ElectronicsPCBInsertion-Radial0:54:120:05:0691%FoundryMoldingMachine0:10:000:06:1238%MetalCuttingCastingDrill1:00:000:09:0085%MetalCuttingCNCMILLING2:00:000:00:00100%MetalCuttingFADALHMC1:45:000:15:2085%MetalFab40TonPress0:48:000:04:0092%MetalFab750TonHydPress2:10:000:42:0068%MetalFab800TonPress6:00:000:10:0097%MetalFabAluminumExtruder1:09:000:02:1297%MetalFabBrakePress0:37:000:04:0089%MetalFabDrawPress1:30:001:00:0033%MetalFabEdgeTrimPress0:24:000:04:0083%MetalFabPilotChange-MufflerPress0:07:000:00:1596%PackagingFlexPackagingLine3:00:000:10:0094%PaperSheeting0:03:000:00:3680%PharmaceuticalCentrifuge0:12:000:02:1282%Plastics250TonInjectionMolder1:06:000:09:1286%PlasticsInjectionMolder2:30:000:06:0096%PlasticsInjectionMolder2:00:000:03:0098%PrintingKidder6-ColorWebPress4:20:001:10:0073%PrintingPressMakeReady9:30:004:20:0054%WoodRouter0:09:000:01:1886%2019/8/2320SMED案例1969年丰田汽车公司更换1000吨级冲床的模具要花4个小时，而德国大众汽车公司只用2个小时。因此，丰田制造厂的经理大原太一下令要求赶超德国。森口花了6个月时间将内部调试从外部调试中分离出来，并逐步改进每一程序中所有相关操作，最后成功地将调试时间缩短到1个半小时。接着，太一又指示他将调试时间减少到3分钟。一开始．森口觉得根本不可能，但很快就想出来新的方法来缩短调试时间。3个月后，他和丰田的主管们一起实现了目标。2019/8/2321Poka-yoke2019/8/2322Mistakes:toerrishuman.(人非圣贤孰能无过）Haveyoueverdonethefollowing:Driventoworkandnotrememberedit?Drivenfromworktohomewhenyoumeanttostopatastore?2019/8/2323Ithappenstoworkerstoo.Workersfinishtheshiftanddon’trememberwhattheyhavedone.Afterbuildinggreenwidgetsallmorni