约束理论---TOC.ppt

TowardsOperationalExcellenceLEANPractitionerProgram TheoryofConstraint約束理論 VisualManagement目視管理 Lean ValueStreamMapping价值流程圖 MaterialControl物料控制 TPM全面生產性維護 LayoutOptimization Cell布局優化 Cell SMED QuickChangeover快速切換 ErrorProofing防錯法 PerformanceMetrics績效指標 TheoryOfConstraints約束理論 LeanDiagnostic精益診斷 ChangeM WasteE改變觀念 消除浪費 LeanOverview精益概述 LeanTools精益工具 TherearemanytoolsandtechniquesintheLean toolbox allsuitedtodifferentapplicationsandcircumstances 在LEAN工具箱中有許多工具和技巧 它們可以用于各種不同的情況 Objective課程目的 UnderstandbasicconceptsofTheoryofConstraint理解約束理論的基本概念PresentandexploretheTOCfivefocusingsteps介紹和探究TOC的五個步驟HowtheDrumBufferRopeprincipleworksDBR原則如何運作Gamestudy游戲練習 OrganizationalGoals組織目標 Quality Inventory Sales Cost TOC Assumptions設想 Thereisafundamentalgoalforeveryorganization 每個組織有一個基本的目標 Everyorganizationisconstrainedinsomeway eitherinternalorexternal 每個組織都被某些因素限制著 不管是內部還是外部 Whiletherearemanycausallinkages therearefewcorecausesthatlimitachievementoforganizationalgoal 當存在許多因果關系時 總有一些關鍵的原因約束著組織達成目標 ROImeasuresorganizationalor system performance wherethethe system isachainofdependentevents thereforethekeymanagementdilemmaissimplyROI衡量了一個組織或系統的績效 這里的系統是指相互依賴的一個鏈 所以關鍵的管理兩難是 DOWEMANAGETHESYSTEM 我們管理這個系統OR還是DOWEMANAGETHECHAINOFEVENTSASINDEPENDENTSYSTEMS 把這一系列的事件當作獨立的系統來管理 ManagementDilemma管理兩難 TOCPhilosophyTOC哲學 TheoryofConstraints TOC isasystem basedphilosophywhichassertsthattheconstraint Bottleneck determinestheperformanceofthesystem TOC是以系統為基礎的哲學 它聲稱瓶頸決定整個系統的績效 Managingfromthekeyleveragepointsprovidesthefocustomaximizethesystem 在杠杆點進行管理可以聚焦于最大化系統的績效 ThetheoryofConstraintsapproachesimprovementatthesystemlevel ratherthanindividualprocessesorisolatedelementsothesystem約束理論方法在于改善系統 而不是單個工序或系統中被隔离的要素 TheTheoryofConstraints瓶頸理論 TOCwasdevelopedbyDr EliyahuM Goldratt aPhysicist 約束理論又稱瓶頸理論 是由物理學家 高德拉特博士提出和發展而來 TOCsuggeststhat TOC提出 Allsystemssimilartochains 所有的系統如同一條鏈 Eachchainiscomposedoflinkswhichvaryinstrengthandcapability 每一條鏈都是由各种多樣化力量和能力的聯接點組成 Inanyindependentchainthereisonelink andonlyone thatisweakerthanalltherest theweakestlink 在任何獨立的鏈里都存在一個聯接 且只有一個 比其它弱 最弱的聯接點 Theweakestlinkistheconstrainttothesystem sperformance 最弱的聯接點就是影響系統績效的約束點 兩种約束 Physical物理方面 People Materials Machine Geography地理Non Physical非物理方面 Policies Rules Measurements Training 瓶頸是整個系統中最無力的環節 約束著組織達成目標 有效產出 品質 交期 成本等 TOC5大步驟 IdentifytheConstraint找出系統的瓶頸2 Decidehowtooptimizetheconstraint決定如何挖盡瓶頸的潛能3 Subordinateotheroperations其他的一切配合上述決定4 Elevatetheconstraint把瓶頸松綁5 Gobacktostep回到第一步 TOCObjective目的 Toimprovethestrengthofthesystemweneedtofindtheweakestlinkinthechainandstrengthenit 要提高系統的力量 我們必須從系統鏈中找出最無力的環節並強化它 ProductionManagementusingTheoryofConstraintsDrum鼓 Buffer緩沖器 Rope DBR DrumBufferRope DBR 定義 Drum鼓 瓶頸 最慢工序 的速度或產能DrumBeat鼓點 瓶頸的進度 用來優化瓶頸效率Buffer緩沖器 放在瓶頸前的以時間為基礎的存貨BufferManagement緩沖器管理 目的是有一個合适的庫存防止瓶頸斷料 同時使周期最小化 瓶頸的進度最優化Rope繩子 原材料發放机制 IntheDBRprocess everyeffortismadetoincreasetheefficiencyoftheconstraintevenatthedetermentofothermeasures Theinventorylevel thebuffer mustensuretheconstraintneverrunsoutofwork Theropemechanismrestrictsallinventorynotneededtoprotecttheconstraintfromenteringthesystem Eachoperationisdirectedtoworkasfastaspossible withoutcompromisingquality whenthereisworkandtositidleifthereisnotwork Drum Buffer Rope Thesloweststep activityinthemanufacturingchainsetsthe DrumBeat 在制造鏈中最慢的工序設置一個鼓點CapacityConstrainedResource CCR 400250350425 Drum Buffer Rope A buffer isplacedin frontofthesloweststepintheprocesstoprotecttheconstraint一個緩沖器放在最慢的工序前來保護瓶頸 Buffer WhatdoBuffersdo緩沖器有什么用 Provideatimebased bufferupperiodically reserveofmaterialtoprotecttheConstraint andtheentireprocess fromlostoperatingtimeduetovariationsin准備一個以時間為基礎的物料儲備來防止瓶頸損失加工時間 這是由于變異來自 set uptimes切換時間processingtimes加工時間machinebreakdowns機器故障traveltime運輸時間delays延期normalprocessstatisticalfluctuations正常工序統計波動Provideanopportunitytooptimizeconstraintschedule提供優化瓶頸的机會eg ganginglikeproductsincreasesrunlengthandincreasesconstraintuptimeandoverallplantoutput增加瓶頸的運行時間 增加瓶頸的開机時間和總產出 Tietothegatingoperationtocontrolthereleaseofrawmaterialintotheprocessstream按照瓶頸工序的需求來發放原材料到生產線 BufferManagement緩沖器管理 3210 Theprofileofthebuffergovernswhattypeofexpeditingwearerequiredtodo nothing plantoexpedite expedite Buffersizeisatrade offbetweenprotectionandleadtimeifbuffersizeisincreased protectionincreases howeversodoesmanufacturingleadtimeThebuffercanbeproperlysizedbymonitoringthe holes Holes telluswheretomakeournextprocessimprovementandwheretheconstraintwillmovewhenthecurrentconstraintiselevatedBecomestheprincipleshopfloorcontrolmechanism Itisneitherlikely nordesirablethatallofthetimebuffercontentprofilesbe100percent Ontheotherhand thetimebuffercontentprofilemustbesufficienttoachievethebuffer sprimarypurposeofprotectingtheconstraint BufferContentProfileBasedon ofWorkAvailable 3210 Constraintisabouttobestarved Workavailable StockupBufferFAST BufferManagement緩沖器管理 Drum Buffer Rope The rope isusedtogatethereleaseofrawmaterialstothepaceoftheconstraintor drumbeat 繩子用來按照瓶頸的節拍或 鼓點 來控制原材料的發放 Rope WhatdoRopesdo繩子有什么用 Providealinkingmechanismforthebuffertotheinitiatingprocesses gatingoperations forastreamofproduction提供一個將緩沖器和起始工序相連的机制保証生產物流Limittheamountofinventorytomanageablelevelbyrestrictingflowintothesystem通過限制物料流進系統來約束存貨達到一個可管理的水平Synchronizetheflowofmaterialtotheconstraintschedule drumbeat 使物流與瓶頸進度保持一致 鼓點 A B C D E RawMaterials FinishedGoods Drum Buffer Rope DBR生產控制 DBRProductionProcess Operation2 Operation3 Operation4 RawMaterials Operation1 Warehouse Customer ConstraintBuffer 1 Salesorderactivatesconstraint ShippingBuffer 2 ConstraintactivatesRMreplenishment pulls stock 3 Constraintalertsdownstreamoperations DBRApplied A B C D E RawMaterials 11PartsperDay 9PartsperDay 5PartsperDay 8PartsperDay 15PartsperDay FinishedGoods SimpleManufacturingLine Task Designaprocesstoproduce5partsperdayattheminimumcost設計一個流程以最小成本來生產5件 天產品 A B C D E 5PartsperDay 5PartsperDay 5PartsperDay 5PartsperDay 5PartsperDay LineBalance WasteElimination RawMaterials FinishedGoods Solution1 問題 生產變異約束了產出 Probabilityallare5 is 0 5 0 5 0 5 0 5 0 5 03 3 chanceofsystemproducing5ormoreperday 50 50 50 50 50 Probabilityof5 pts day 5 1Pts day LineBalance WasteElimination RawMaterials FinishedGoods 5 1Pts day 5 1Pts day 5 1Pts day 5 1Pts day ImpactofVariability Assumeavariationinoutputof 20 A B C D E Chanceof 5 Chanceof 5 50 A B C D E 11Pts day 9Pts day 5Pts day 8Pts day 15Pts day Drum Buffer Rope Solution2 TOCProcessControl DBR RawMaterials FinishedGoods A B C D E 11 2Pts day 9 2Pts day 5 1Pts day 8 2Pts day 15 3Pts day Drum Buffer Rope ImpactofVariability 變异的影響 TOCProcessControl DBR 50 chanceofsystemproducing5ormoreperday RawMaterials FinishedGoods Assumeavariationinoutputof 20 TOCMeasures KeyDBRMeasures Keyelementstoensure關鍵因素确保 ONTI