Lean-Production(精益生产)

Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Copyright 2006 John Wiley&Sons,Inc.,15-,*,Click to edit Master title style,BeniAsllaniUniversityofTennesseeatChattanooga,LeanProduction,OperationsManagement-5,th,Edition,Chapter15,RobertaRussell&BernardW.Taylor,III,Copyright2006JohnWiley&Sons,Inc.,LectureOutline,BasicElementsofLeanProduction,BenefitsofLeanProduction,ImplementingLeanProduction,LeanServices,2,Copyright2006JohnWiley&Sons,Inc.,LeanProduction,Doingmorewithlessinventory,fewerworkers,lessspace,Just-in-time(JIT),smoothingthe,flow,ofmaterialtoarrivejustasitisneeded,“JIT,”,”and,“,“LeanProduction,”,”areusedinterchangeably,Muda,waste,anythingotherthanthatwhichaddsvaluetotheproductorservice,3,Copyright2006JohnWiley&Sons,Inc.,WasteinOperations,4,Copyright2006JohnWiley&Sons,Inc.,WasteinOperations(cont.),5,Copyright2006John Wiley&Sons,Inc.,WasteinOperations(cont.),6,Copyright2006John Wiley&Sons,Inc.,BasicElements,Flexibleresources,Cellularlayouts,Pull productionsystem,Kanbanproductioncontrol,Smalllotproduction,Quicksetups,Uniform productionlevels,Totalproductive maintenance,Suppliernetworks,7,Copyright2006John Wiley&Sons,Inc.,FlexibleResources,Multifunctionalworkers,perform morethanonejob,general-purposemachinesperformseveral basic functions,Cycletime,time required fortheworker to complete onepass throughthe operationsassigned,Takt time,pacesproduction to customer demand,8,Copyright2006John Wiley&Sons,Inc.,StandardOperatingRoutineforaWorker,9,Copyright2006John Wiley&Sons,Inc.,CellularLayouts,Manufacturing cells,comprisedofdissimilarmachinesbrought together to manufacture afamily of parts,Cycletime is adjusted to match takttimebychangingworkerpaths,10,Copyright2006John Wiley&Sons,Inc.,Cellswith WorkerRoutes,11,Copyright2006John Wiley&Sons,Inc.,WorkerRoutes Lengthen as VolumeDecreases,12,Copyright2006John Wiley&Sons,Inc.,Pull System,Materialispulledthroughthesystem whenneeded,Reversaloftraditionalpush systemwherematerialispushedaccording to aschedule,Forcescooperation,Prevent overand underproduction,Whilepush systemsrelyona predeterminedschedule,pullsystemsrely on customer requests,13,Copyright2006John Wiley&Sons,Inc.,Kanbans,Card which indicatesstandardquantityofproduction,Derived fromtwo-bininventorysystem,Maintaindiscipline of pullproduction,Authorizeproductionandmovementofgoods,14,Copyright2006John Wiley&Sons,Inc.,SampleKanban,15,Copyright2006John Wiley&Sons,Inc.,OriginofKanban,a)Two-bin inventory systemb)Kanban inventory system,Reorder,card,Bin 1,Bin 2,Q,-,R,Kanban,R,R,Q,=order quantity,R,=reorder point-demand during lead time,16,Copyright2006John Wiley&Sons,Inc.,TypesofKanban,Production kanban,authorizes productionofgoods,Withdrawal kanban,authorizes movement of goods,Kanbansquare,a markedarea designatedtoholditems,Signalkanban,a triangularkanban usedtosignal productionatthe previous workstation,Materialkanban,used to order material in advanceofaprocess,Supplier kanban,rotates betweenthefactory and suppliers,17,Copyright2006JohnWiley&Sons,Inc.,18,Copyright2006JohnWiley&Sons,Inc.,19,Copyright2006JohnWiley&Sons,Inc.,20,Copyright2006JohnWiley&Sons,Inc.,Determining Number of Kanbans,where,N,=number of kanbansor containers,d,=averagedemand over some time period,L,=lead time toreplenishan order,S,=safety stock,C,=container size,No.of Kanbans=,average demand during lead time+safety stock,container size,N,=,dL,+,S,C,21,Copyright2006JohnWiley&Sons,Inc.,Determining Number of Kanbans:Example,d,=150bottles per hour,L,=30minutes=0.5 hours,S,=0.10(150 x 0.5)=7.5,C,=25bottles,Roundup to 4(to allow some slack)or down to 3(to force improvement),N,=,=3.3 kanbans or containers,dL,+,S,C,(150 x 0.5)+7.5,25,75+7.5,25,22,Copyright2006JohnWiley&Sons,Inc.,SmallLots,Require less space and capitalinvestment,Moveprocessescloser together,Makequality problems easier to detect,Makeprocessesmoredependenton each other,23,Copyright2006JohnWiley&Sons,Inc.,Inventory Hides Problems,24,Copyright2006JohnWiley&Sons,Inc.,Less Inventory Exposes Problems,25,Copyright2006JohnWiley&Sons,Inc.,Componentsof Lead Time,Processingtime,Reduce number of items orimprove efficiency,Movetime,Reduce distances,simplify movements,standardizeroutings,Waitingtime,Better scheduling,sufficient capacity,Setup time,Generally the biggest bottleneck,26,Copyright 2006 JohnWiley&Sons,Inc.,Quick Setups,Internalsetup,Canbe performedonly when aprocessisstopped,Externalsetup,Canbe performedinadvance,SMEDPrinciples,Separateinternal setupfromexternal setup,Convertinternalsetup to external setup,Streamline all aspects of setup,Performsetup activitiesinparalleloreliminate them entirely,27,Copyright 2006 JohnWiley&Sons,Inc.,Common Techniques for Reducing SetupTime,28,Copyright 2006 JohnWiley&Sons,Inc.,Common Techniques for Reducing SetupTime(cont.),29,Copyright 2006 JohnWiley&Sons,Inc.,Common Techniques for Reducing SetupTime(cont.),30,Copyright 2006 JohnWiley&Sons,Inc.,UniformProduction Levels,Result fromsmoothing productionrequirements,Kanban sy