经典教材成本会计(CMA必备)

CHAPTER20InventoryManagement,Just-in-Time,andBackflushCostingInventoryManagementin

RetailOrganizationsInventoryManagementisplanning,coordinating,andcontrollingactivitiesrelatedtotheflowofinventoryinto,through,andoutofanorganizationCostsAssociatedwith

GoodsforSaleManaginginventoriestoincreasenetincomerequireseffectivelymanagingcoststhatfallintothesefivecategories:PurchasingCostsOrderingCostsCarryingCostsStockoutCostsQualityCostsManagementofInventoryCostsPurchasingCosts–thecostofgoodsacquiredfromsuppliers,includingfreightOrderingCosts–thecostsofpreparingandissuingpurchaseorders;receivingandinspectingtheitemsincludedintheorders;andmatchinginvoicesreceived,purchaseorders,anddeliveryrecordstomakepaymentsManagementofInventoryCostsCarryingCosts–thecoststhatarisewhileholdinginventoryofgoodsforsale.Thisincludestheopportunitycostoftheinvestmenttiedupininventory,andcostsassociatedwithstorageStockoutCosts–thecoststhatresultwhenacompanyrunsoutofaparticularitemforwhichthereiscustomerdemand(stockout)andthecompanymustactquicklytomeetthedemandorsufferthecostsofnotmeetingitManagementofInventoryCostsQualityCosts–thecoststhatresultwhenfeaturesandcharacteristicsofaproductorservicearenotinconformancewithcustomerspecifications.Thesecostsinclude:PreventionAppraisalInternalFailureExternalFailureTheFirstStepinManaging

GoodsforSaleThefirstdecisioninmanaginggoodsforsaleishowmuchtoorderofagivenproductEconomicOrderQuality(EOQ)isadecisionmodelthatcalculatestheoptimalquantityofinventorytoorderunderagivensetofassumptionsBasicEOQAssumptionsThereareonlyorderingandcarryingcostsThesamequantityisorderedateachreorderpointDemand,purchase-orderleadtime,orderingcosts,andcarryingcostsareknownwithcertaintyPurchasingcostsperunitareunaffectedbythequantityorderedNostockoutsoccurEOQignorespurchasingcosts,stockoutcosts,andqualitycostsEOQFormulaD=DemandinunitsforspecifiedperiodP=RelevantorderingcostsperpurchaseorderC=RelevantcarryingcostsofoneunitinstockforthetimeperiodusedforDOrderingPointsTheseconddecisioninmanaginggoodsforsaleiswhentoorderagivenproductReorderPoint–thequantitylevelofinventoryonhandthattriggersanewpurchaseorderInventoryManagementand

SafetyStockSafetyStockisinventoryheldatalltimesregardlessofthequantityofinventoryorderedusingtheEOQmodelSafetystockisabufferagainstunexpectedincreasesindemand,uncertaintyaboutleadtime,andunavailabilityofstockfromsuppliersEstimatingInventory-RelatedRelevantCostsCarryingCostsStockoutCostsOrderingCostsCarryingCostsRelevantinventorycarryingcostsconsistofrelevantincrementalcostsandtherelevantopportunitycostofcapitalRelevantIncrementalCosts–thosecostsofthepurchasingfirmthatchangewiththequantityofinventoryheldOpportunityCostsRelevantOpportunityCostofCapital–thereturnforgonebyinvestingcapitalininventoryratherthanelsewhere.ThiscostequalstherequiredrateofreturnmultipliedbytheunitcoststhatvarywiththenumberofunitspurchasedandareincurredatthetimetheunitsarereceivedCostofaPredictionErrorThreestepsindeterminingthecostofapredictionerror:Computethemonetaryoutcomefromthebestactionthatcouldbetaken,giventheactualamountofthecostperpurchaseorderComputethemonetaryoutcomefromthebestactionbasedontheincorrectamountofthepredictedcostperpurchaseorderComputethedifferencebetweenSteps1&2Just-in-TimePurchasingJust-in-Time(JIT)PurchasingisthepurchaseofmaterialsorgoodssotheyaredeliveredjustasneededforproductionorsalesJITispopularbecausecarryingcostsareactuallymuchgreaterthanestimatedbecausewarehousing,handing,shrinkage,andinvestmentcostshavenotbeencorrectlyestimatedJITPurchasingJITreducesthecostofplacingapurchaseorderbecause:Long-termpurchasingagreementsdefinepriceandqualityterms.IndividualpurchaseorderscoveredbythoseagreementsrequirenoadditionalnegotiationregardingpriceorqualityCompaniesareusingelectroniclinkstoplacepurchaseordersatasmallfractionoftraditionalmethods(phoneormail)Companiesareusingpurchase-ordercardsRelevantCostsinJITPurchasingPurchasingCostsStockoutCostsQualityCostsJITPurchasingand

Supply-ChainAnalysisSupplychaindescribestheflowofgoods,services,andinformationfromtheinitialsourcesofmaterialsandservicestothedeliveryofproductstoconsumers(bothinsideandoutsidethefirm)Supplychainmembersshareinformationandplan/coordinateactivitiesSupplierevaluationsarecriticaltoJITpurchasingimplementationInventoryManagementandMaterialsRequirementsPlanningMaterialsRequirementsPlanning(MRP)–a“push-through”systemthatmanufacturesfinishedgoodsforinventoryonthebasisofdemandforecastsMRPInformationInputsMRPusesthreeinformationsourcestodeterminethenecessaryoutputsateachstageofproductionDemandforecastsoffinalproductsAbillofmaterialsdetailingthematerials,components,andsubassembliesforeachfinalproductThequantitiesofmaterials,components,andproductinventoriestodeterminethenecessaryoutputsateachstageofproductionMRPTakesintoaccountleadtimetopurchasematerialsandtomanufacturecomponentsandfinishedproductsSetsamasterproductionschedulespecifyingquantitiesandtimingofeachitemtobeproducedTheoutputofeachdepartmentispushedthroughtheproductionlinewhetheritisneededornot“PushThrough”mayresultinanaccumulationofinventoryInventoryManagementand

JITProductionJIT(Lean)Production–isa“demand-pull”manufacturingsystemthatmanufactureseachcomponentinaproductionlineassoonasandonlywhenneededbythenextstepintheproductionlineDemandtriggerseachstepoftheproductionprocess,startingwithcustomerdemandforafinishedproductandworkingbackwardDemandpullsanorderthroughtheproductionlineJITProductionGoalsMeetcustomerdemandinatimelybasis,withhigh-qualityproducts,atthelowestpossiblecost.JITProductionFeaturesProductionisorganizedinmanufacturingcells,agroupingofallthedifferenttypesofequipmentusedtomakeagivenproductWorkersarehiredandtrainedtobemulti-skilled(cross-trained)DefectsareaggressivelyeliminatedSetuptimeisreducedSuppliersareselectedonthebasisoftheirabilitytodeliverqualitymaterialsinatimelymannerOtherBenefitsofJITProductionLoweroverheadcostsLowerinventorylevelsHeightenedemphasisonimprovingqualitybyeliminatingthespecificcausesofrework,scrap,andwasteShortermanufacturingleadtimesJITandEnterpriseResourcePlanningSystems(ERP)JITsuccesshingesonthespeedofinformationflowsfromcustomerstomanufacturerstosuppliersERPisasystemwithasingledatabasethatcollectsdataandfeedsthemintosoftwareapplicationssupportingallofafirm’sbusinessactivitiesERPgivesmanagers,workers,customers,andsuppliersaccesstooperatinginformationERPcanbeexpensive,large,andunwieldyPerformanceMeasuresandControlinJITFinancialperformancemeasuressuchasinventoryturnoverratioNonfinancialperformancemeasuresoftime,inventory,andqualitysuchas:ManufacturingleadtimesUnitsproducedperhourDaysofinventoryonhandSetuptimeasa%oftotalmanufacturingtimeNumberofdefectiveunitsasa%oftotalunitsproducedBackflushCo