物流专业英语（第5版） 电子课件 Ch7

InventoryManagementChapter7ChapterOutlineConceptofInventoryPurposesofInventoryTypesofInventoryPartI

ConceptandTypesofInventoryPartII

InventoryManagementStrategies

MaterialRequirementsPlanning(MRP)DistributionRequirementsPlanning(DRP)Vendor-ManagedInventory(VMI)Just-In-TimeInventoryManagementPartIII

SupplementaryReading:Casestudy:JITintheSmogCo.ProductionSystemPerformanceMeasureforProductionSystemChangestoCustomerRequirementsTraditionalReactiontoCustomerDemandsforBetterServicePartI

ConceptandTypesofInventory

ConceptofInventoryInventoryisalargeandcostlyinvestment.Bettermanagementoffirminventoriescanimprovecashflowandreturnoninvestment.Theinventoryrequirementsofafirmdependonthenetworkstructureandthedesiredlevelofcustomerservice.Theoretically,afirmcouldstockeveryitemsoldinafacilitydedicatedtoserveeachcustomer.Fewbusinessoperationscouldaffordsuchalargeinventorycommitmentbecausetheriskandtotalcostwouldbeprohibitive.Theobjectiveistoachievethedesiredcustomerservicewiththeminimuminventory,consistentwithlowesttotalcost.PurposesofInventory

Facilitateseconomiesofscale.Managementmaydecide,forexample,topurchaselargequantitiesofaniteminordertoqualifyforadiscount.Orlowertransportationcostsmayberealizedbyshippinglargerquantitiesatonetime.Similarly,alongproductionrunmaysignificantlyreducemanufacturingcosts.Ineverycase,inventoryisbeingutilizedasawaytoobtainsavingsinotherpartsofthelogisticssystem.Offersameansofbalancingsupplyanddemand.Somefirmscanonlyselltheirproductsatcertaintimesoftheyear.Inordertoutilizetheirfixedinvestmentinbuildingsandequipmentandmaintainaskilledlaborforce,managersmaydecidedtoproduceallyearandstorethefinishedgoodsuntilthesellingseasonarrives.Providesprotectionfromuncertaindemand.Despitemanagement’sbestforecastingefforts,demandcanneverbeknownwithabsolutelycertainty.Similarly,transportvehiclesbreakdown,rawmaterialsmaysuddenlybeunavailable.Andmanufacturinglinesmaystop.Forallofthesereasons,inventoryisutilizedtoensurethatcustomerneedsaremetevenwhentheproductionprocessitselfisinterrupted.Specialization.Inventorymakesitpossibleforafirm’splantstospecializeintheproductsthatitmanufactures.Thefinishedproductscanbeshippedtofieldwarehouseswheretheyaremixedtofillcustomerorders.Theeconomiesthatresultfromthelongerproductionrunsandfromsavingsintransportationcostmorethanoffsetsthecostofadditionalhandling.Inventoryasabuffer.Inventoryisheldthroughoutthesupplychaintoactasabufferforthefollowingcriticalinterfaces:

Supplies-procurement(purchasing)

Procurement-production

Production-marketing

Marketing-distribution

Distribution-intermediary

Intermediary-consumer/userExcessiveinventory.Excessiveinventoriesmaycompensatefordeficienciesinbasicdesignofalogisticsnetworkandtosomedegreeinferiormanagement.However,excessiveinventoryusedasacrutchwillultimatelyresultinhigherthannecessarytotallogisticscost.Symptomsofpoorinventorymanagementaredescribedasfollowing:

Lossofcustomers

Increasingnumberofback-orders

Increasinginvestmentininventorywithback-ordersremainingconstant

Increasingnumberoforderscanceled

Periodiclackofsufficientstoragespace

Deterioratingrelationshipswithintermediaries,astypifiedbydealercancellationsanddecliningorders

LargequantitiesofobsoleteitemsTypesofInventoryForamanufacturer,inventoryriskislongterm.Themanufacturer’sinventorycommitmentstartswithrawmaterialandcomponentparts,includeswork-in-process,andendswithfinishedgoods.Inaddition,finishedgoodsareoftenpositionedinwarehousesinanticipationofcustomerdemand.Insomesituations,manufacturersarerequiredtoconsigninventorytocustomerfacilities.Ineffect,thispracticeshiftsallinventoryrisktothemanufacturer.Althoughamanufacturertypicallyhasanarrowerproductlinethanaretailerorwholesaler,themanufacturer’sinventorycommitmentisdeepandoflongduration.Awholesalerpurchaseslargequantitiesfrommanufacturersandsellssmallerquantitiestoretailers.Theeconomicfunctionofawholesaleristhecapabilitytoprovideretailcustomerswithassortedmerchandisefromdifferentmanufacturersinspecificquantities.Whenproductsareseasonal,thewholesalermayberequiredtotakeaninventorypositionfarinadvanceofthesellingseason,thusincreasingdepthanddurationofrisk.Oneofthegreatestchallengesofwholesalingisproduct-lineexpansiontothepointwherethewidthofinventoryriskapproachestheretailers,whiledepthanddurationofriskremaintraditionalforthewholesalers.Inrecentyears,retailclientshavealsoforcedalargeincreaseindepthanddurationbyshiftinginventoryresponsibilitybacktowholesalers.Facedwiththiswidthofinventory,retailersattempttoreduceriskbypressingmanufacturersandwholesalerstoassumegreaterandgreaterinventoryresponsibility.Specialtyretailers,incontrasttomassmerchandisers,normallyexperiencelesswidthofinventoryriskasaresultofhandlingnarrowerassortments;however,theymustassumegreaterriskwithrespecttodepthanddurationofinventoryholding.Ifabusinessplanstooperateatmorethanonelevelofthedistributionchannel,itmustbepreparedtoassumerelatedinventoryrisk.Forexample,thefoodchainthatoperatesaregionalwarehouseassumesriskrelatedtothewholesaleroperationoverandabovethenormalretailoperations.Foraretailer,inventorymanagementisaboutbuyingandsellingspeed.Theretailerpurchasesawidevarietyofproductsandassumesasubstantialriskinthemarketingprocess.Retailerinventoryriskcanbeviewedaswidebutnotdeep.Duetothehighcostofstorelocation,retailersplaceprimeemphasisoninventoryturnoveranddirectproductprofitability.Inventoryturnoverisameasureofinventoryvelocityandiscalculatedastheratioofannualsalesdividedbyaverageinventory.Althoughretailersassumeapositionofriskonavarietyofproducts,theirpositiononanyoneproductisnotdeep.Riskisspreadacrossmorethan30,000StockKeepingUnits(SKUs)inatypicalsupermarket.Adiscountstoreofferinggeneralmerchandiseandfoodoftenexceeds25,000SKUs.Afull-linedepartmentstoremayhaveasmanyas50,000SKUs.dedicatedto/ˈdedɪkeɪtɪd/adjprohibitive/prəˈhɪbətɪv/adjtransportvehiclesspecialization/ˌspeʃəlaɪˈzeɪʃən/n.buffer/ˈbʌfə/n.procurement/prəˈkjʊəməntproʊˈkjʊr-/n.

intermediary/ˌɪntəˈmiːdiəri/n.excessive/ɪkˈsesɪv/adj.deficiency/dɪˈfɪʃənsi/n.compensatefor/ˈkɒmpənseɪt/v.crutch/krʌtʃ/n.symptom/ˈsɪmptəm/n.backorderperiodic/ˌpɪəriˈɒdɪk/adj.deteriorate/dɪˈtɪəriəreɪt/v.obsolete/ˈɒbsəliːt/adj.inventoryturnoverinventoryvelocitystockkeepingunits(SKUs)专用于禁止的，抑制的，太贵的运输工具专门化，专业化缓冲器获得，采购中间人，中间商过量的短缺，缺少补偿，弥补拐杖，支撑症状，象征迟延订单周期性的恶化过期的，过时的，已废弃的库存周转率库存周转速度存货单位NewWordsandExpressionsPartII

InventoryManagementStrategies

MaterialRequirementsPlanning(MRP)MRPdealsspecificallywithsupplyingmaterialsandcomponentpartswhosedemanddependsuponthedemandforaspecificendproduct.Essentially,MRPbeginsbydetermininghowmuchofthefinalproductcustomersdesire,andwhentheyneedit.ThenMRPbreaksdownthetimingandneedforcomponents(allofwhichcouldhavedifferentleadtimes)baseduponthatscheduledend-productneed.AnMRPsystemconsistsofasetoflogicallyrelatedprocedures,decisionrules,andrecords,whicharedesignedtotranslateamasterproductionscheduleintotime-phasednetinventoryalsore-plansnetrequirementsasaresultofchanges.MRPminimizesinventorytotheextentthatthemasterproductionscheduleaccuratelyreflectswhatisneededtosatisfycustomerdemand.Iftheproductionscheduledoesnotmatchdemand,thecompanywillhavetoomuchofsomeitemsandtoolittleofothers.Becausethemasterproductionscheduledrivestheneedforparts,MRPissaidtobeapullsystem.Inotherwords,theproductionschedule“pulls”componentsthroughthesysteminordertomeetmanufacturingneeds.DistributionRequirementsPlanning(DRP)

DRPisamoresophisticatedplanningapproachthatconsidersmultipledistributionstagesandthecharacteristicsofeachstage.DRPisthelogicalextensionofmanufacturingrequirementsplanning,althoughthereisonefundamentaldifferencebetweenthetwotechniques.MRPisdeterminedbyaproductionschedulethatisdefinedandcontrolledbytheenterprise.Ontheotherhand,DRPisguidedbycustomerdemand,whichisnotcontrollablebytheenterprise.So,whileMRPgenerallyoperatesinadependentdemandsituation,DRPoperatesinanindependentenvironmentwhereuncertaincustomerdemanddeterminesinventoryrequirements.Themanufacturingrequirementsplanningcomponentcoordinatestheschedulingandintegrationofmaterialsintofinishedgoods.MRPcontrolsinventoryuntilmanufacturingorassemblyiscompleted.DRPthentakescoordinationresponsibilityoncefinishedgoodsarereceivedintheplantwarehouse.Vendor-ManagedInventory(VMI)

Vendor-ManagedInventory(VMI)isanapproachtoinventoryandorderfulfillmentwherebythesupplier,notthecustomer,isresponsibleformanagingandreplenishinginventory.Thisappearsatfirstsighttocountertheprincipleofpullscheduling,becausetheprecedingprocess(themanufacturer)isdecidinghowmanyandwhentosendtothenextprocess(theretailer).Inpractice,thebasisonwhichdecisionswillbemadeisagreedwiththeretailerbeforehand,andisbasedontheretailer’ssalesinformation.UnderVMI,thesupplierassumesresponsibilityformonitoringsalesandinventory,andusesthisinformationtotriggerreplenishmentorders.Ineffect,supplierstakeoverthetaskofstockreplenishment.TheimmediatebenefitofVMIisaccesstodataon:

customersales;

inventorylevelsatthecustomers.Ononeside,thismayhelpthesuppliertoprovidebettercontrolofthesupplychainandsodeliverbenefitsforboththecustomerandthemselves.Ontheotherside,havingthesuppliertakethedecisiononthereplenishmentaimstominimizetheimpactofdemandamplification.Inthelongerterm,suppliersshouldintegratedemandinformationintotheirorganizationanddevelopthecapabilitytodriveproductionwithit.Thishelpstoreplacethetraditionalpushschedulingwithpullscheduling,basedonmeetingknowndemandinstantaneouslyoutofmanufacturing.OtherthanthepracticaldifficultiesofsettingupaVMIsystem,anumberofproblemscanpreventtheabovebenefit:

Unwillingnesstosharedata.Retailersmaybeunwillingtosharetheirmarketingplansandproductrangestrategieswithmanufacturers.

Seasonalproducts.ThebenefitsofVMIarequicklyawayinfashionandseasonalproducts,especiallyapparel.

Investmentandrestructuringcosts.AdoptingaVMIapproachincursahighinvestmentbythecustomerandsupplier,andalsotakestimeandeffort.

Retailervulnerability.VMIwillmaketheretailermoredependentonthem.

Lackofstandardprocedures.Customersmayaskfordifferenttaggingmethodsorlabeling.Withmanyindustrialproductsthereisnobar-codestandard.

Systemmaintenance.Itneedsalotmaintenancetotheinventoryrecorderrorsduetoincorrectpartcounts,mislabeling,damage,lossandtheft.

JustInTimeInventoryManagement

Intheearly1970s,ToyotaMotorManufacturingadoptedJITsystem,anewproductionstrategythatusedlittleinventory,shortenedcycletimes,improvedquality,andeliminatedwasteandcostsinthesupplychain.ItwasalsoadoptedbyAmericanandEuropeanautomakersinresponsetothegrowingsuccessoftheirJapanesecompetitors.LaterJITconceptspreadtootherindustriessuchascomputers,andbecamepopularinmanufacturingstrategiesaroundtheworld.Just-In-Timeisaphilosophyofcontinuousandforcedproblemsolving.WithJIT,suppliesandcomponentsare“pulled”throughasystemtoarrivewheretheyareneededwhentheyareneeded.Whengoodunitsdonotarrivejustasneeded,a“problem”hasbeenidentified.ThismakesJITanexcellenttooltohelpoperationsmanagersaddvaluebydrivingoutwasteandunwantedvariability.BecausethereisnoexcessinventoryorexcesstimeinaJITsystem,costsfromunneededinventoryareeliminatedandthroughputimproved.Consequently,thebenefitsofJITareparticularlyhelpfulinsupportingstrategiesofrapidresponseandlowcost.Moreinventoryturns.Becausethereislessstockonhand,theinventorythatismaintainedstaysforashorterperiodoftime.Betterquality.HighqualityproductsmustbereceivedwithaJITsystem,otherwisetheentirebenefitproductionprocesscollapses.DisadvantagesofJITLesswarehousespace.Whenthereislessinventory,fewerand/orsmallerwarehousesarerequired.AdvantagesofJITRiskofstock-outs.Whenfirmseliminateinventory,theriskofstockingoutcanrise.Increasedpurchasingcosts.Theoretically,JITmeansobtainingsmalleramountsmorefrequently,whichgenerallywillnotgetpurchasingdiscountsassociatedwithbuyinglargequantitiesatonetime.Smallchannelmembersmaysuffer.JITmayallowstrongorganizationstoshifttheirinventorytosmallerfirmsinthechannel.Environmentalissues.JITcanleadtohigherlevelsoftrafficcongestionandairpollutionbecauseofadditionaltransportationrequired.JITisalsoestablishedpracticeinrestaurants,wherecustomersexpectit,andanecessityintheproducebusiness,wherethereislittlechoice.PacificPre-CutProduce,a$14millionfruitandvegetableprocessingcompanyinTracy,California,holdsinventorytozero.Buyersareinactionintheveryearlyhoursofthemorning.At6a.m.,productioncrewsshowup.Ordersforveryspecificcutsandmixturesoffruitandvegetablesaladsandstir-fryingredientsforsupermarkets,restaurants,andinstitutionalkitchenspourinfrom8a.m.until4p.m.Shippingbeginsat10p.m.andcontinuesuntilthelastorderisfilledandloadedat5a.m.thenextmorning.Inventoriesareonceagainzero,thingsarerelativelyquiet,andthentheroutinestartsagain.PacificPre-CutProducehasaccomplishedacompletecycleofpurchase,manufacture,andshippinginabout24hours.VPBobBorzonecallstheprocesstheultimateinmass-customization.“Webuyeverythingasabulkcommodity,thensliceanddiceittofittheexactrequirementsoftheenduser.Thereare20differentstir-frymixes.Somecustomerswantthesnowpeasclippedonbothends,somejustonone.Somewantonlyredbellpeppersinthemix,someonlyyellow.Youtailortheproducttothecustomer’srequirements.You’retryingtomeettheneedofalotofendusers,andeachrestaurantandretailerwantstolookdifferent.”MaterialRequirementsPlanning(MRP)物料需求计划DistributionRequirementsPlanning(DRP)分销需求计划，配送需要计划plantwarehouse工厂仓库hybrid/ˈhaɪbrɪd/n混合物assumption/əˈsʌmpʃən/n假设eliminate/ɪˈlɪməneɪt/v.automaker/ˈɔːtəʊˌmeɪkə/n.throughput/ˈθruːpʊt/n.stock/stɒk/n.replenishment/rɪˈplenɪʃ/n.trafficcongestionmasscustomizationtactics/ˈtæktɪks/n.bulk/bʌlk/n.slice/slaɪs/v.dice/daɪs/v.stir-fry/stɜː-fraɪ/n.clip/klɪp/n.消除，消灭汽车制造商产量，生产能力存货补给交通堵塞大量定制化策略，战术大量，大块切成薄片切成小方块用旺火炒，煎炒修剪NewWordsandExpressionsPartIII

SupplementaryReading:

Casestudy:JITintheSmogCo.ProductionSystemPerformanceMeasureforProductionSystem

SmogCo.isasmallsupplierofwell-engineeredcomponents.Itproducesarangeofproductsgroupedintofamilies.Productionofoneofthehighervolumeproductfamilieshasbeenorganizedintoaflowprocessmadeupoffoursteps,whichfollowoneaftertheotherinsequence.Changeoverfromoneproducttoanotherissimple,buttakesaround10minutespermachine.Tominimizedelayscausedbychangeovers,productstendtobemadeinbatches.Thesebatchesmovefromonesteptothenext,wheretheyqueueonafirstin,firstoutbasistobeworkedon,afterwhichtheymovetothenextstep.Keymeasuresoftheperformanceofthisprocessaretheutilizationofpeopleandofmachines.Theobjectiveistokeeputilizationofbothashighaspossible.FredHollis,theSmogproductionmanager,feltpleasedwithperformanceashelookedoutacrossthefactory.Hewaspleasedbecausehismachinesandpeoplewerebusy,therewereplentyoffinishedgoodsonhand,whichthesalesteamcouldusetosupplycustomers,andtherewasstocktocalluponifproductdemandincreased.Everythingseemedtobeundercontrol.ChangestoCustomerRequirementsThemotivationtochangefromthecurrentsystemhasbeenlowinthepast,astheprocessatSmogCo.isareliableone,whichhasworkedwellforthecompany.Thebigthreecustomers,whotakethree-quartersofsales,tendtoorderthesamethingsinsimilarquantitiesoneweekinadvanceofdelivery.Withaproductionleadtimeofthreeweeks,SmogCo.usesaforecasttoscheduleproductionandmakesurethatfinishedgoodsstockswillbeavailabletomeetpredicteddemand.Consistentdemandmeansthatforecastsareoftenclosetorealdemand,sostockoutsarerare.Infacttheonlytimethisoccurredwasanincidentacoupleofyearsago,whenakeymachinewentdownandaspareparttookalongtimetosource.Currentinventorylevelsnowincludesafetystocktoprovidecoveragainstasimilarprobleminthefuture.Whenthecompanyfoundthatcertainfinishedgoodsweresellingslowly,thesalesteamwasparticularlygoodatfindingawaytomovethem.Sometimespriceswerecut;atothertimessalesusedspecialpromotions.Ifproductionwastoohigh,ortheforecastwasabitoptimistic,thentherewerewaysofsellingsurplusstock,andthesalesteamseemedtoenjoythechallenge.Recently,however,thiswell-understoodpositionbegantochange.Themaincustomersstartedtouseanumberofnewstrategiestocompetewitheachother.Firstoneandthenasecondofthemannouncedthatitwillbereducingthecall-offtimeforitsproductsfromoneweektotwoworkingdays.Atthesametimetheyarealllookingfora5percentcostreduction,andaredemandingqualityimprovement.TraditionalReactiontoCustomerDemandsforBetterService

ThecombinationofdemandsforbetterservicescausedSmogmanagementsomeconcern.Theobviousresponsetothechangesinorderingpatternswastoincreasestocklevelstocaterforunexpectedvariationsindemand.Thisapproachhadworkedbefore,whenitwasusedtojustifythesafetystocksthatcoveredproductionproblems.Itseemedworthtryingagain,sostockswereincreased.Thingswentwelloverthefirstfewmonths,duringwhichtimedeliveryperformanceremainedgoods,whilethecustomerswentaheadwiththeirplantoreducetheorderleadtime.Keepingupwiththeseordersprovidedtheproducti