-12InventoryManagement(运营管理,英文版)

TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-1?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458OperationsManagement

InventoryManagement

Chapter12TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-2?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458OutlineGlobalCompanyProfile:Harley-DavidsonFunctionsofInventoryTypesofInventoryInventoryManagementABCAnalysisRecordAccuracyCycleCountingControlofServicesInventoryTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-3?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Outline-continuedInventoryModelsIndependentversusDependentDemandHolding,Ordering,andSetupCostsInventoryModelsforIndependentDemandBasicEconomicOrderQuantity(EOQ)ModelMinimizingCostsReorderPointsModelProductionOrderQuantityModelQuantityDiscountModelsFixed-PeriodSystemTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-4?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Outline-continuedProbabilisticModelswithConstantLeadTimeFixedPeriodSystemsTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-5?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458LearningObjectivesExplainwhatinventoryisExplainhowinventoryisclassifiedExplainABCAnalysisandCycleCountingCompareinventorymodelsUseinventorymodelstofindhowmuchandwhentoorderTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-6?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Harley-Davidson1970s-intensecompetitionfromHondaandYamahaEmphasizedqualityimprovementRequired:tighterinventorycontrolJITproductandprocessimprovementsPrimarilyètotalqualitycontrolprogramdrivenbyinventorycontrolpoliciesTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-7?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458StockofmaterialsStoredcapacityExamples?1995CorelCorp.?1984-1994T/MakerCo.?1984-1994T/MakerCo.?1995CorelCorp.WhatisInventory?TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-8?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458TheFunctionsofInventoryProvideastockofgoodstomeetanticipatedcustomerdemandandprovidea搒election?ofgoodsDecouplesuppliersfromproductionandproductionfromdistributionAllowonetotakeadvantageofquantitydiscountsToprovideahedgeagainstinflationToprotectagainstshortagesduetodeliveryvariationTopermitoperationstocontinuesmoothlywiththeuseof搘ork-in-processTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-9?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458HighercostsItemcost(ifpurchased)Ordering(orsetup)costCostsofforms,clerks?wagesetc.Holding(orcarrying)costBuildinglease,insurance,taxesetc.DifficulttocontrolHidesproductionproblemsDisadvantagesofInventoryTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-10?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458TypesofInventoryRawmaterialWork-in-processMaintenance/repair/operatingsuppliesFinishedgoodsTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-11?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458InventoryProcessstageDemandTypeNumber&ValueOtherRawMaterialWIPFinishedGoodsIndependentDependentAItemsBItemsCItemsMaintenanceDependentOperating?1984-1994T/MakerCo.InventoryClassificationsTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-12?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Runtime:JobisatmachineandbeingworkedonSetuptime:Jobisattheworkstation,andtheworkstationisbeing"setup."Queuetime:Jobiswhereitshouldbe,butisnotbeingprocessedbecauseotherworkprecedesit.Movetime:ThetimeajobspendsintransitWaittime:Whenoneprocessisfinished,butthejobiswaitingtobemovedtothenextworkarea.Other:"Just-in-case"inventory.TheMaterialFlowCycleOtherWaitTimeMoveTimeQueueTimeSetupTimeRunTimeInputCycleTimeOutputTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-13?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Divideson-handinventoryinto3classesAclass,Bclass,CclassBasisisusuallyannual$volume$volume=AnnualdemandxUnitcostPoliciesbasedonABCanalysisDevelopclassAsuppliersmoreGivetighterphysicalcontrolofAitemsForecastAitemsmorecarefullyABCAnalysisTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-14?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458020406080100050100150%ofInventoryItems%Annual$UsageABCClass%$Vol%ItemsA8015B1530C555ClassifyingItemsasABCTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-15?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458PhysicallycountingasampleoftotalinventoryonaregularbasisUsedoftenwithABCclassificationAitemscountedmostoften(e.g.,daily)CycleCountingTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-16?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458AdvantagesofCycleCountingEliminatesshutdownandinterruptionofproductionnecessaryforannualphysicalinventoriesEliminatesannualinventoryadjustmentsProvidestrainedpersonneltoaudittheaccuracyofinventoryAllowsthecauseoferrorstobeidentifiedandremedialactiontobetakenMaintainsaccurateinventoryrecordsTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-17?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458TechniquesforControllingServiceInventoryInclude:Goodpersonnelselection,training,anddisciplineTightcontrolofincomingshipmentsEffectivecontrolofallgoodsleavingthefacilityTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-18?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Independentversus

DependentDemandIndependentdemand-demandforitemisindependentofdemandforanyotheritemDependentdemand-demandforitemisdependentuponthedemandforsomeotheritemTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-19?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Holding,Ordering,andSetupCostsHoldingcosts-associatedwithholdingor揷arrying?inventoryovertimeOrderingcosts-associatedwithcostsofplacingorderandreceivinggoodsSetupcosts-costtoprepareamachineorprocessformanufacturinganorderTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-20?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458HoldingCostsObsolescenceInsuranceExtrastaffingInterestPilferageDamageWarehousingEtc.TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-21?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458DeterminingInventoryHoldingCostsCategoryHousingcostsMaterialhandlingcostsLaborcostfromextrahandlingInvestmentcostsPilferage,scrap,andobsolescenceCostasa%ofInventoryValue6%(3-10%3%(1-3.5%03%(3-

5%)11%(6-24%)3%(2-5%)TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-22?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458OrderingCostsSuppliesFormsOrderprocessingClericalsupportEtc.TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-23?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458SetupCostsClean-upcostsRe-toolingcostsAdjustmentcostsEtc.TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-24?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458FixedorderquantitymodelsEconomicorderquantityProductionorderquantityQuantitydiscountProbabilisticmodelsFixedorderperiodmodelsHelpanswertheinventoryplanningquestions!?1984-1994T/MakerCo.InventoryModelsTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-25?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458KnownandconstantdemandKnownandconstantleadtimeInstantaneousreceiptofmaterialNoquantitydiscountsOnlyorder(setup)costandholdingcostNostockoutsEOQAssumptionsTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-26?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458OrderQuantityAnnualCostHoldingCostCurveTotalCostCurveOrder(Setup)CostCurveOptimal

OrderQuantity(Q*)EOQModel

HowMuchtoOrder?TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-27?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458MoreunitsmustbestoredifmoreorderedPurchaseOrderDescriptionQty.Microwave1OrderquantityPurchaseOrderDescriptionQty.Microwave1000OrderquantityWhyHoldingCostsIncreaseTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-28?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458CostisspreadovermoreunitsExample:Youneed1000microwaveovensPurchaseOrderDescriptionQty.Microwave1PurchaseOrderDescriptionQty.Microwave1PurchaseOrderDescriptionQty.Microwave1PurchaseOrderDescriptionQty.Microwave11Order(Postage$0.32)1000Orders(Postage$320)OrderquantityPurchaseOrderDescriptionQty.Microwave1000WhyOrderCostsDecreaseTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-29?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458EOQModel

WhenToOrderReorderPoint(ROP)TimeInventoryLevelAverage

Inventory(Q*/2)LeadTimeOptimalOrderQuantity

(Q*)TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-30?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458DerivinganEOQDevelopanexpressionforsetupororderingcostsDevelopanexpressionforholdingcostSetsetupcostequaltoholdingcostSolvetheresultingequationforthebestorderquantityTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-31?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458OptimalOrderQuantityExpectedNumberofOrdersExpectedTimeBetweenOrdersWorkingDays/YearWorkingDays/Year========Q*DSHNDQ*TNdDROPdL2D=DemandperyearS=Setup(order)costperorderH=Holding(carrying)costd=DemandperdayL=LeadtimeindaysEOQModelEquationsTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-32?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458AnswershowmuchtoorderandwhentoorderAllowspartialreceiptofmaterialOtherEOQassumptionsapplySuitedforproductionenvironmentMaterialproduced,usedimmediatelyProvidesproductionlotsizeLowerholdingcostthanEOQmodelProductionOrderQuantityModelTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-33?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458ReasonsforVariabilityinProductionMostvariabilityiscausedbytoleratingwasteorbypoormanagement.Specificcausesinclude:employees,machines,andsuppliersproduceunitsthatdonotconformtostandards,arelateorarenottheproperquantityengineeringdrawingsorspecificationsare inaccurateproductionpersonneltrytoproducebefore drawingsorspecificationsarecompletecustomerdemandsareunknownTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-34?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458POQModelInventoryLevelsInventoryLevelTimeSupplyBeginsSupplyEndsProductionportionofcycleDemandportionofcyclewithnosupplyTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-35?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458TimeInventoryLevelProduction

PortionofCycleMax.Inventory

Q?1-d/p)Q*SupplyBeginsSupplyEndsInventorylevelwithnodemandDemandportionofcyclewithnosupplyPOQModelInventoryLevelsTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-36?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458D=DemandperyearS=SetupcostH=Holdingcostd=Demandperdayp=ProductionperdayPOQModelEquationsOptimalOrderQuantityMax.InventoryLevelSetupCostHoldingCost==-=*=*=QH*dpQDQSp*1(0.5*H*Q-dp1)-dp1()2*D*S()TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-37?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Answershowmuchtoorder&

whentoorderAllowsquantitydiscountsReducedpricewhenitemispurchasedinlargerquantitiesOtherEOQassumptionsapplyTrade-offisbetweenlowerprice&increasedholdingcostQuantityDiscountModelTransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-38?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458LowestcostnotindiscountrangeQuantityDiscountModel

HowMuchtoOrder?OrderQuantityTotalCostTCforDiscount1DiscountQuantity1TCforDiscount2TCforDiscount3Discount

Quantity2QuantityOrderedPrice1Price2Price3TransparencyMasterstoaccompanyOperationsManagement,5E(Heizer&Render)12-39?1998byPrenticeHall,Inc.ASimon&SchusterCompanyUpperSaddleRiver,N.J.07458Answerhowmuch&whentoorderAllowdemandtovaryFollowsnormaldistrib