jit准时生产方式_jit推式与拉式系统

及時化生產系統,1,及時化(justintime，JIT)概述,提出者：豐田汽車副社長，大野耐一(TaiichiOhno)。意義將需要的物品在必須的時間供應必須的品質與數量到需要的地點。目的消除混亂使系統彈性化降低籌置與前置時間存量最小化消除浪費,及時化生產系統,2,JIT目標和建築架構的歸納,產品設計,流程設計,人員因素,製造規劃,避免中斷,使系統有彈性,排除浪費,平衡迅速的流程,最終目標,支援目標,建築架構,及時化生產系統,3,常見的資源浪費1,超額生產(overproduction)等候時間(waitingtime)不必要的運送(unnecessarytransporting)存貨(inventory)加工浪費(processingwaste)不必要的生產步驟產出瑕疵品,及時化生產系統,4,常見的資源浪費2,無效的工作方法(inefficientworkmethod)不佳的佈置和物料搬運模式，增加在製品存貨產品不良再製成本消費者不滿意造成銷售損失,及時化生產系統,5,WasteinOperations,及時化生產系統,6,WasteinOperations,及時化生產系統,7,WasteinOperations,及時化生產系統,8,ThePrinciplesoftheTOYOTAProductionSystem(TPS)1,Allworkmustbecompletelyspecifiedastocontent,sequence,timing,andoutcome.Everycustomer-supplierconnectionmustbedirect,unambiguouslyspecifyingthepeopleinvolved,theformandquantityoftheservicesorgoodstobeprovided,thewaytherequestsaremadebyeachcustomer,andtheexpectedtimeinwhichtherequestswillbemet.,及時化生產系統,9,ThePrinciplesoftheTOYOTAProductionSystem(TPS)2,Thepathwayforeveryserviceandproductmustbesimpleanddirect.Anyimprovementtothesystemmustbemadeinaccordancewiththescientificmethod,undertheguidanceofateacher,atthelowestpossibleorganizationallevel.,及時化生產系統,10,BasicElementsofJIT1,標準的零件(產品設計)模組化設計(產品設計)高產能的系統(產品設計)可同時生產(產品設計),將員工視為資產(人員/組織的要素)訓練員工，使其變成多能工(人員/組織的要素)持續改善(人員/組織的要素)成本會計(人員/組織的要素)領導與專案管理(人員/組織的要素),及時化生產系統,11,BasicElementsofJIT2,Cellularlayouts(製程設計Pullproductionsystem(製造規劃與控制)Flexibleresources(製程設計)Kanbanproductioncontrol(製造規劃與控制)Small-lotproduction(製程設計),Quicksetups(製程設計)Uniformproductionlevels(製造規劃與控制)Qualityatthesource(製程設計)Totalproductivemaintenance(製造規劃與控制)Suppliernetworks(製造規劃與控制),及時化生產系統,12,FlexibleResources,Multifunctionalworkers(多能工)PerformmorethanonejobGeneralpurposemachines(通用設備)PerformseveralbasicfunctionsStudyoperators每一工作站從前一站拉拔所需產出。,及時化生產系統,17,KanbanProductionControlSystem(看板生產管制系統),KanbancardindicatesstandardquantityofproductionDerivedfromtwo-bininventorysystem(雙倉制)KanbanmaintainsdisciplineofpullproductionProductionkanban(生產看板)authorizesproductionWithdrawalkanban(提領看板)authorizesmovementofgoods,及時化生產系統,18,ASampleKanban,及時化生產系統,19,TheOriginofKanban,及時化生產系統,20,TypesofKanbansDualkanbans,及時化生產系統,21,Single-CardKanbanSystem,及時化生產系統,22,Storagearea,Emptycontainers,Fullcontainers,Single-CardKanbanSystem,Receivingpost,Kanbancardforproduct1,Kanbancardforproduct2,及時化生產系統,23,Storagearea,Emptycontainers,Fullcontainers,Single-CardKanbanSystem,Receivingpost,Kanbancardforproduct1,Kanbancardforproduct2,及時化生產系統,24,Storagearea,Emptycontainers,Fullcontainers,Single-CardKanbanSystem,Receivingpost,Kanbancardforproduct1,Kanbancardforproduct2,及時化生產系統,25,Storagearea,Emptycontainers,Fullcontainers,Single-CardKanbanSystem,Receivingpost,Kanbancardforproduct1,Kanbancardforproduct2,及時化生產系統,26,Storagearea,Emptycontainers,Fullcontainers,Single-CardKanbanSystem,Receivingpost,Kanbancardforproduct1,Kanbancardforproduct2,及時化生產系統,27,Storagearea,Emptycontainers,Fullcontainers,Single-CardKanbanSystem,Receivingpost,Kanbancardforproduct1,Kanbancardforproduct2,Fabricationcell,O1,O2,O3,O2,及時化生產系統,28,看板系統singlekanban,及時化生產系統,29,Dualkanbanvs.singlekanban,DualkanbanIsusedwhenmaterialisnotnecessarilymovingbetweentwoconsecutiveprocesses,orwhenthereismorethanoneinputtoaprocessandtheinputsaredispersedthroughoutthefacility.SinglekanbanIsusedwhentheprocessesaretightlylinked.,及時化生產系統,30,TypesofKanbans,KanbanSquareMarkedareadesignedtoholditemsSignalKanbanTriangularkanbanusedtosignalproductionatthepreviousworkstationMaterialKanbanUsedtoordermaterialinadvanceofaprocessSupplierKanbansRotatebetweenthefactoryandsuppliers,及時化生產系統,31,TypesofKanbanskanbansquareandkanbanracks,及時化生產系統,32,TypesofKanbanssignalkanbans,及時化生產系統,33,看板管理系統之規則,不要把不良品交給後製程。由後製程到前製程來領取零件。前製程僅生產將被後製程領用去的數量。生產必須平衡。看板只做為微調整的手段，其張數必須減到最少。製程必須安定化、合理化。,及時化生產系統,34,Single-CardKanbanSystem,KANBAN,PartNumber:1234567ZLocation:Aisle5Bin47LotQuantity:6Supplier:WS83Customer:WS116,EachcontainermusthaveacardAssemblyalwayswithdrawsfromfabrication(pullsystem)ContainerscannotbemovedwithoutakanbanContainersshouldcontainthesamenumberofpartsOnlygoodpartsarepassedalongProductionshouldnotexceedauthorization,及時化生產系統,35,看板(容器)數量之決定1,K=容器數量。d=工作中心之計劃使用率(預期每日需求)。p=每箱容器零件之平均加工時間。W=在生產過程中之平均等候時間，加上每箱物料的搬運時間。C=標準容器之零件容量。X=政策變數。反應生產系統的效率(10%以內),及時化生產系統,36,看板(容器)數量之決定2,及時化生產系統,37,看板(容器)數量之決定3,whereN=numberofkanbansorcontainersd=averagedemandoversometimeperiodL=leadtimetoreplenishanorderS=safetystockC=containersize,及時化生產系統,38,容器數量決定範例,某汽車零件公司生產4輪傳動車的方向盤及暫停系統中的搖桿手臂組合。一般1箱零件在製造週期中需要0.02天的加工及0.08天的物料處理和等候時間。零件每日的需求為2000個單位。管理部門認為搖桿手臂組合的需求不確定，所以其安全庫存為需求量的10%。若每箱內各有22個零件，則應授權的箱子數量為多少。,及時化生產系統,39,小批量(Small-lotproduction)的效益,降低在製品存貨減少因品質發生問題時所產生的檢驗和重加工成本減少儲存空間問題更容易顯現增加生產彈性易於進行作業平衡,及時化生產系統,40,InventoryHidesProblems,及時化生產系統,41,LowerLevelsofInventoryExposeProblems,及時化生產系統,42,ComponentsofLeadTime(前置時間的元素),ProcessingtimeReducenumberofitemsorimproveefficiencyMovetimeReducedistances,simplifymovements,standardizeroutingsWaitingtimeBetterscheduling,sufficientcapacitySetuptimeGenerallythebiggestbottleneck,及時化生產系統,43,快速籌置(Quicksetups),Single-digitsetupThegoalofhavingasetuptimeoflessthan10minutes.快速換模又稱一分鐘換模術(single-minuteexchangeofdies,SMED),及時化生產系統,44,快速籌置的實施步驟,1.將換模作業流程劃分外部整備作業與內部整備作業。2.儘可能把內部整備作業改變成外部整備作業。3.消除內部整備所需的調整作業。4.外部整備作業的標準化。5.推動平行作業。6.利用機械提高換模效率。7.其他管理部門的充分配合。,及時化生產系統,45,CommonTechniquesforReducingSetupTime1,及時化生產系統,46,CommonTechniquesforReducingSetupTime2,及時化生產系統,47,CommonTechniquesforReducingSetupTime3,及時化生產系統,48,平準化生產(UniformProduction),ResultsfromsmoothingproductionrequirementsKanbansystemscanhandle+/-10%demandchangesThewaytoreducevariabilityinproductionSmoothsdemandacrossplanninghorizonMixed-modelassemblysteadiescomponentproduction,及時化生產系統,49,平準化範例1,TheAPPofTOYOTA:4500vehiclesperweek.Twofullshifts,fivedaysperweek450pershift(480minutes)Threemodelsareproduced:Camry(C),Avalon(A),andSienna(S).200Camry,150Avalons,and100SiennaspershiftCycletime:480/450=1.067(min),及時化生產系統,50,平準化範例2,First200Cs150As100SsHighaveragecycleinventorylevelLumpyrequirementsSecond4Cs3As2SsThecycle=9(1.067)=9.60(50timespershift),及時化生產系統,51,平準化範例3,ThirdCSCACACSAThesetuptimesmustbeveryshort.ComponentrequirementsissteadyCapacityrequirementsaresmoothed,及時化生產系統,52,QualityattheSource1,Jidoka(自働化)在生產過程中自動偵測缺點Andon(安童)在每個工作站裝置燈號系統，以指示問題及落後狀態。Undercapacityschedulingallowsforplanning,problemsolving&maintenance,及時化生產系統,53,QualityattheSource2,防呆裝置日文發音為POKAYOKE，是指在模具，工具，機器設備上設計防止錯誤(不良)發生的裝置，一旦作業員做錯或需要作業上的警示時，防呆裝置可以預防或使機器停下來，確保不產生不良品。目視管理系統(visualcontrol)：係透過顯示板之顯示得以快速且明顯地發現異常、浪費、故障、斷料等現場不順暢之情形，而達到能速謀對策的一種管理系統。,及時化生產系統,54,VisualControl,及時化生產系統,55,VisualControl,及時化生產系統,56,VisualControl,及時化生產系統,57,Kaizen(改善),ContinuousimprovementRequirestotalemploymentinvolvementEssenceofJITiswillingnessofworkerstoSpotqualityproblemsHaltproductionwhennecessaryGenerateideasforimprovementAnalyzeproblemsPerformdifferentfunctions,及時化生產系統,58,TotalProductiveMaintenance(TPM),BreakdownmaintenanceRepairstomakefailedmachineoperationalPreventivemaintenanceSystemofperiodicinspection&maintenancetokeepmachinesoperatingTPMcombinespreventivemaintenance&totalqualityconcepts,及時化生產系統,59,TPMRequiresManagementto:,DesignproductsthatcanbeeasilyproducedonexistingmachinesDesignmachinesforeasieroperation,changeover,maintenanceTrain&retrainworkerstooperatemachinesPurchasemachinesthatmaximizeproductivepotentialDesignpreventivemaintenanceplanspanninglifeofmachine,及時化生產系統,60,導入JIT的基礎5S運動,及時化生產系統,61,SupplierPolicies1,LocateneartothecustomerUsesmall,sideloadedtrucksandshipmixedloadsConsiderestablishingsmallwarehousesneartothecustomerorconsolidatingwarehouseswithothersuppliers,及時化生產系統,62,SupplierPolicies2,UsestandardizedcontainersandmakedeliveriesaccordingtoaprecisedeliveryscheduleBecomeacertifiedsupplierandacce