InventoryManagement教学讲解课件

InventoryManagementChapter121InventoryManagementChapter12IndependentandDependentDemandDependentDemandUsedintheproductionofafinalorfinishedproduct.Isderivedfromthenumberoffinishedunitstobeproduced.E.g.ForEachCar:4-wheels.Wheelsarethedependentdemand.IndependentDemandSoldtosomeone.Precisedeterminationofquantityimpossibleduetorandomness.Forecastingthenumberofunitsthatcanbesold.FocusonmanagementofIndependentDemandItems.2IndependentandDependentDemaTypesofInventory

RawmaterialComponentsWork-in-progressFinishedgoodsDistributionInventoryMaintenance/repair/operatingsupply(MRO)3TypesofInventoryRawmateriTomeetanticipateddemand.Tosmoothproductionrequirements.Todecoupleoperations.Toprotectagainststockouts.Totakeadvantageofeconomiclotsize.Tohedgeagainstpriceincreasesortotakeadvantageofquantitydiscounts.FunctionsofInventory4Tomeetanticipateddemand.FunObjectivesofInventoryControlInventoryManagementhastwomainconcerns:LevelofCustomerService.Costoforderingandcarryinginventories. Achievesatisfactorylevelsofcustomerservicewhilekeepinginventorycostswithinreasonablebounds.2fundamentaldecisions:

--TimingofOrders--SizeofOrdersMeasuresofeffectiveInventoryManagement:CustomerSatisfaction.InventoryTurnover=COGS/AverageInventory.DaysofInventory:expectednumberofdaysofsalesthatcanbesuppliedfromexistinginventory.

i.e.whentoorderandhowmuchtoorder.5ObjectivesofInventoryControCharacteristicsofInventorySystemsDemand

--

ConstantVsVariable --KnownVsRandomLeadtime-KnownVsRandomReviewTime-ContinuousVsPeriodicExcessdemand-BackorderingVsLostSalesChangingInventory6CharacteristicsofInventoryS

PeriodicVsContinuousReviewSystemsPeriodicReviewSystem

Inventorylevelmonitoredatconstantintervals.Decisions:Toorderornot.Howmuchtoorder?

Realizeeconomiesinprocessingandshipping.Riskofstockoutbetweenreviewperiods.Timeandcostofphysicalcount.ContinuousReviewSystem

Inventorylevelmonitoredcontinuously.Decisions:Whentoorder? Howmuchtoorder?Shortagescanbeavoided.Optimalorderquantitycanbedetermined.Addedcostofrecordkeeping.Moreappropriateforvaluableitems7PeriodicVsContinuousRevRelevantInventoryCostsItemprice(Costofanitem).Holdingcosts:Variablecostsdependentupontheamountofinventoryheld(e.g.:capital&opportunitycosts,storage&insurance,riskofobsolescence).Expressedeitherasapercentageofunitpriceorasadollaramountperunit.Ordering&setupcosts:Fixedcostofplacinganorder(e.g.:clericalaccounting&physicalhandling)orsettingupproduction(e.g.:lostproductiontochangetools&cleanequipment).Expressedasafixeddollaramountperorderregardlessofordersize.Shortagecosts:Resultwhendemandexceedsthesupplyofinventoryon-hand.(stock-out)Lostprofit,expediting&backorderingexpenses.Aresometimesdifficulttomeasure,&theymaybesubjectivelyestimated.8RelevantInventoryCostsItempWhyControlInventoryCostVsServiceUnder-stock:Frequentstock-outsLostsales,lossofcustomergoodwillLowlevelofcustomerserviceOver-stock:ExcessinventoryCostsoforderingandcarryinginventoryincreaseObjective:Establishaninventorycontrolsystemtofindabalancebetweencostandservice:Whentoorder?Howmuchtoorder?9WhyControlInventoryCostVsSLot-for-lot:

Orderexactlywhatisneeded.Fixedorderquantity:Orderapredeterminedamounteachtime.Min-maxsystem:Wheninventoryfallstoasetminimumlevel,orderuptothepredeterminedmaximumlevel.Orderenoughfornperiods:Theorderquantityisdeterminedbytotaldemandfortheitemforthenextn-periods.Periodicreview:Atspecifiedintervals,orderuptoapredeterminedtargetlevel.OrderingQuantityApproaches10Lot-for-lot:OrderingQuantityDivideson-handinventoryinto3classes:Aclass,Bclass,Cclass(very-->moderate-->least:important).Basisisusuallyannual$volume: $volume=AnnualdemandxUnitcostClassA:15%-20%ofitemsbut70%-80%dollarusage.ClassB:30%-35%ofitemsbut15%-20%dollarusage.ClassC:50%-60%ofitemsbut5%-10%dollarusage.PoliciesbasedonABCanalysis:DevelopclassAsuppliersmoreGivetighterphysicalcontrolofAitemsForecastAitemsmorecarefullyClassificationSystem11Divideson-handinventoryintoExampleClassifytheinventoryitemsasA,BandCbasedonannualdollarvalue.72%oftotalvalueand17%ofitems:ClassA.25%ofvalueand33%ofitems:ClassB.3%oftotalvalueand50%ofitems:ClassC.12ExampleClassifytheinventoryBasicEconomicOrderQuantity(EOQ).EconomicProductionQuantity(EPQ) (EOQwithnon-instantaneousdelivery).QuantityDiscountModel.Economic-OrderQuantityModels13BasicEconomicOrderQuantityOnlyoneproductisinvolved.Demandisknown&constant-nosafetystockisrequired.Leadtimeisknown&constant.Noquantitydiscountsareavailable.Ordering(orsetup)costsareconstant.Alldemandissatisfied(noshortages).Theorderquantityarrivesinasingleshipment.EOQModelAssumptions14Onlyoneproductisinvolved.EInventoryLevel(Cycle)QROPQuantityonhandReceiveOrderPlaceOrderReceiveOrderLeadTime15InventoryLevel(Cycle)QROPQuaTotalannualcosts=Annualorderingcosts+AnnualholdingcostsEOQModel16Totalannualcosts=AnnualorMinimizetheTCbyorderingtheEOQ:EOQ:TotalCostEquationsD=AnnualDemand.H=AnnualInventoryHolding/CarryingCostperUnit.S=Ordering/SetupCostperorder.LengthofanOrderCycle(timebetweenorders)=(Q/D)years.17MinimizetheTCbyorderingthExampleAlocaldistributorforanationaltirecompanyexpectstosellapproximately9,600beltedradialtiresforacertainsizeandtreaddesignnextyear.Annualcarryingcostis$16pertire,andorderingcostis$75.Thedistributoroperates288daysayear. A. WhatistheEOQ? B. Howmanytimesperyeardoesthestoreorder? C. Whatisthelengthofanordercycle? D. WhatisthetotalannualcostiftheEOQquantityisordered?PiddingManufacturingassemblessecuritymonitors.Itpurchases3,600black-and-whitecathoderaytubesayearat$65each.Orderingcostis$31perorder,andannualcarryingcostperunitis20%ofthepurchaseprice.Computetheoptimalorderquantityandthetotalannualcostoforderingandcarryingtheinventory.18ExampleAlocaldistributorfor Assumptions:SameastheEOQexcept:inventoryarrivesinincrements&isdrawndownasitarrives.EconomicProductionQuantityModel19 Assumptions:SameastheEOQAdjustedtotalcost:Maximuminventory:Adjustedorderquantity:CycleTime:Q/d.RunTime(productionphaseofthecycle):Q/p.where,d=demand(usagerate);p=productionrate;S=ordering/setupcost;D=AnnualdemandandH=AnnualHoldingcost.EPQEquations20Adjustedtotalcost:EPQEquatiExample Atoymanufactureruses48,000rubberwheelsperyearforitspopulardumptruckseries.Thefirmmakesitsownwheels,whichitcanproduceatarateof800perday.Thetoytrucksareassembleduniformlyovertheentireyear.Carryingcostis$1perwheelayear.Setupcostforaproductionrunofwheelsis$45.Thefirmoperates240daysperyear.Determinethe: A. Optimalrunsize. B. Minimumtotalannualcostforcarryingandsetup. C. Cycletimefortheoptimalrunsize. D. Runtime.21Example AtoymanufactureruseSameastheEOQ,except:Unitpricedependsuponthequantityordered.Adjustedtotalcostequation:QuantityDiscountModel22SameastheEOQ,except:QuantiTotalCostswithPurchasingCost(PD)CostEOQTCwithPDTCwithoutPDAnnualpurchasingcost=(PD)0QuantityAddingPurchasingcost

doesn’tchangeEOQ23TotalCostswithPurchasingCoQuantityDiscountRepresentationOrder PriceQuantity perBox1to44 $2.0045to69 $1.7070ormore $1.40PD@$2.00eachPD@$1.70eachPD@$1.40each04570QuantityTotalCostTC@$1.70eachTC@$2.00eachTC@$1.40each24QuantityDiscountRepresentatiQuantityDiscountModelTheobjectiveistoidentify‘anorderquantity’thatwillrepresentthelowesttotalcostfortheentiresetofcurves.2GeneralCases:CarryingCostisconstant.SingleEOQ.Sameforalltotalcostcurves.CarryingCostisapercentageofthePrice.DifferentEOQfordifferentprices.LowercarryingcostmeanslargerEOQ.Asunitpricedecreases,eachcurveEOQwillbetotherightofthenexthighercurves’EOQ. 25QuantityDiscountModelTheobjCalculatetheEOQatthelowestprice.DeterminewhethertheEOQisfeasibleatthatpriceWillthevendorsellthatquantityatthatprice.Ifyes,Stop–ifno,Continue.CheckthefeasibilityofEOQatthenexthigherpriceContinueuntilyouidentifyafeasibleEOQ.Calculatethetotalcosts(includingpurchaseprice)forthefeasibleEOQmodel.Calculatethetotalcostsofbuyingattheminimumquantityallowedforeachofthecheaperunitprices.Comparethetotalcostofeachoption&choosethelowestcostalternative.

QuantityDiscountProcedure26CalculatetheEOQatthelowesThemaintenancedepartmentofalargehospitalusesabout816casesofliquidcleanerannually.Orderingcostsare$12,carryingcostsare$4percaseayear,andthenewpricescheduleindicatesthatordersoflessthan50caseswillcost$20percase,50to79caseswillcost$18percase,80to99caseswillcost$17percase,andlargerorderswillcost$16percase.Determinetheoptimalorderquantityandthetotalcost.SurgeElectricuses4,000toggleswitchesayear.Switchesarepricedasfollows:1to499,90centseach;500to999,85centseach;and1,000ormore,80centseach.Itcostsapproximately$30toprepareanorderandreceiveit,andcarryingcostsare40percentofpurchasepriceperunitonanannualbasis.Determinetheoptimalorderquantityandthetotalannualcost.Examples27ThemaintenancedepartmentofROP=d(LT)WhentoOrder?

where

LT=Leadtime(indaysorweeks)

d=Dailyorweeklydemandrate28ROP=d(LT)WhentoOrder?wh

Anofficesupplystoresellsfloppydisksetsatafairlyconstantrateof6,000peryear.Theaccountingdept.statesthatitcosts8$toplaceanorderandannualholdingcostare20%ofthepurchaseprice3$perunit.Ittakes4daystoreceiveanorder.Assuminga300-dayyear,find:

a)OptimalordersizeandROP. b)Annualorderingcost,annualcarryingcost. c)Howmanyordersaregivenayearandwhatisthetimebetweentheorders?Example29AnofficesupplystoresellWhatifDemandisUncertain?ROPTimeQuantityonhand30WhatifDemandisUncertain?ROUncertainDemand(LeadTime)SafetyStockModels:Usethesameorderquantity(EOQ)basedonexpected(average)annualdemand.DetermineROPtosatisfyatargetServiceLevel:Probabilitythatdemandwillnotexceedsupplyduringleadtime(Leadtimeservicelevel).Percentofannualdemandimmediatelysatisfied(Annualservicelevelorfill-rate).Equals:1-stock-outriskSafetyStock:

Stockthatisheldinexcessofexpecteddemandduetovariabledemandrateand/orleadtime.31UncertainDemand(LeadTime)SaDemandvariability.Leadtimevariability.Order-cycleservicelevel:Fromamanagerialstandpoint,determinetheacceptableprobabilitythatdemandduringleadtimewon’texceedon-handinventory.Riskofastockout:1–(servicelevel).AddingSafetyStock32Demandvariability.AddingSafeR=reorderpointd=averagedailydemandLT=leadtimeindaysz=numberofstandarddeviationsassociatedwithdesiredservicelevelσ=standarddeviationofdemandduringleadtime (Assumesthatanyvariabilityindemandrateorleadtimecanbeadequatelydescribedbyanormaldistribution)AdjustedReorderPointEquation33R=reorderpointAdjustedReoExample

Supposethatthemanagerofaconstructionsupplyhousedeterminedfromhistoricalrecordsthatdemandforsandduringleadtimeaverages50tons.Inaddition,supposethemanagerdeterminedthatdemandduringleadtimecouldbedescribedbyanormaldistributionthathasameanof50tonsandastandarddeviationof5tons.Answerthesequestions,assumingthatthemanageriswillingtoacceptastockoutriskofnomorethan3percent. A. Whatvalueofzisappropriate? B. Howmuchsafetystockshouldbeheld? C. Whatreorderpointshouldbeused?34Example SupposethatthemanagReorderPoint-ContinuedWhendataonleadtimedemandisnotreadilyavailable,cannotusethestandardformula.Usethedailyorweeklydemandandthelengthoftheleadtimetogenerateleadtimedemand.Ifonlydemandisvariable,thenuse , andtheROPis:35ReorderPoint-ContinuedWhendIfonlyleadtimeisvariable,thenuse,andtheROPis:Ifbothdemandandleadtimesvariable,then36Ifonlyleadtimeisvariable,Example

Arestaurantusesanaverageof50jarsofaspecialsauceeachweek.Weeklyusageofsaucehasastandarddeviationof3jars.Themanageriswillingtoacceptnomorethana10percentriskofstockoutduringleadtime,whichistwoweeks.Assumethedistributionofusageisnormal. A.Whichoftheaboveformulaisappropriateforthis situation?Why? B.Determinethevalueofz. C.DeterminetheROP.37Example ArestaurantusesanaShortageandServiceLevelE.g.:Supposethestandarddeviationofleadtimedemandisknowntobe20unitsandleadtimedemandisapproximatelyNormal.Foraleadtimeservicelevelof90percent,determinetheexpectednumberofunitsshortforanyordercycle.Whatleadtimeservicelevelwouldanexpectedshortageof2unitsimply?38ShortageandServiceLevelE.g.Giventhefollowinginformation,determinetheexpectednumberofunitsshortperyear.D=1,000;Q=250;E(n)=2.5.Givenaleadtimeservicelevelof90%,D=1,000,Q=250,andσdLT=16,determine(a)theannualservicelevel,and(b)theamountofcyclesafetystockthatwouldprovideanannualservicelevelof.98(Given:E(z)=0.048for90%leadtimeservicelevel).39GiventhefollowinginformatioFixed-OrderIntervalModelOrdergroupingscanproducesavingsinorderingandshippingcosts.Canhavevariationsindemand,leadtime,orinboth.Ourfocusisonlyondemandvariability,withconstantleadtimes.

OI=OrderInterval(lengthoftimebetweenorders)Imax=Maximumamountofinventory(alsocalledorder-up-to-levelpoint)=Expecteddemandduringprotectioninterval+SafetystockE.g.:Giventhefollowinginformation,determinetheamounttoorder.40Fixed-OrderIntervalModelOrdeSingle-PeriodModelsGoalistoidentifytheorderquantity,orstockinglevel,thatwillminimizethelong-runtotalexcessandshortagecost.Usedfororderperishables.Analysisfocusontwocosts:ShortageandExcess.2kindsofproblems:Demandcanbeapproximatedusingacontinuousdistribution.Demandcanbeapproximatedusingadiscretedistribution.41Single-PeriodModelsGoalistoContinuousStockingLevels:DiscreteStockingLevels:E.g.:SweetciderisdeliveredweeklytoCindy’sCiderBar.Demandvariesuniformlybetween300litersand500litersperweek.Cindypays20centsperliterfortheciderandcharges80centsperliterforit.Unsoldciderhasnosalvagevalueandcannotbecarriedoverintothenextweekduetospoilage.Findtheoptimalstockinglevelanditsstockoutriskforthatquantity.E.g.:Cindy’sCiderBaralsosellsablendofcherryjuiceandapplecider.DemandfortheblendisapproximatelyNormal,withameanof200litersperweekandastandarddeviationof10litersperweek.Cs=60centsperliter,andCe=20centsperliter.Findtheoptimalstockinglevelfortheapplecherryblend.E.g.:Historicalrecordsontheuseofsparepartsforseverallargehydraulicpressesaretoserveasanestimateofusageforsparesofanewlyinstalledpress.Stockoutcostsinvolvedowntimeexpensesandspecialorderingcosts.Theseaverage$4,200perunitshort.Sparescost$800each,andunusedpartshavezerosalvage.Determinetheoptimalstockinglevel.42ContinuousStockingLevels:DisExamples Alargebakerybuysflourin25-poundbags.Thebakeryusesanaverageof4,860bagsayear.Preparinganorderandreceivingashipmentofflourinvolvesacostof$4perorder.Annualcarryingcostsare$30perbag. A. Determinetheeconomicorderquantity. B. Whatistheaveragenumberofbagsonhand? C. Computethetotalcostoforderingandcarryingflour. D. Iforderingcostweretoincreaseby$1perorder,how muchwouldthataffecttheminimumtotalannual orderingandcarryingcost?43Examples AlargebakerybuysfExamples Alargelawfirmusesanaverageof40packagesofcopierpaperaday.Eachpackagecontains500sheets.Thefirmoperates260daysayear.Storageandhandlingcostsforthepaperare$1ayearperpack,anditcostsapproximately$6toorderandreceiveashipmentofpaper.Whatordersizewouldminimizetotalannualorderingandcarryingcosts?Computethetotalannualcostusingyourordersizefromparta.Exceptforrounding,areannualorderingandcarryingcostsalwaysequalattheEOQ?Theofficemanageriscurrentlyusinganordersizeof400packages.Thepartnersofthefirmexpecttheofficetobemanaged“inacost-efficientmanner.”Wouldyourecommendthattheofficemanagerusetheoptimalordersizeinsteadof400packages?Justifyyouranswer. 44Examples AlargelawfirmusesExamples

Achemicalformproducessodiumbisulphatein100-kgbags.Demandforthisproductis20tonsperday.Thecapacityforproducingtheproductis50tonsperday.Setupcosts$100,andstorageandhandlingcostsare$50pertonperyear.Thefirmoperates200daysayear.(Note:1ton=1,000kg)Howmanybagsperrunareoptimal?Whatwouldtheaverageinventorybeforthislotsize?Determinetheapproximatelengthofaproductionrun,indays.Abouthowmanyrunsperyearwouldtherebe?Howmuchcouldthecompanysaveannuallyifthesetupcostcouldbereducedto$25perrun?45Examples AchemicalformproduExamples

Acompanyisabouttobeginproductionofanewproduct.Themanagerofthedepartmentthatwillproduceoneofthecomponentsfortheproductwantstoknowhowoftenthemachinetobeusedtoproducetheitemwillbeavailableforotherwork.Themachinewillproducetheitematarateof200unitsaday.Eightyunitswillbeuseddailyinassemblingthefinalproduct.Assemblywilltakeplacefivedaysaweek,50weeksayear.Themanagerestimatesthatitwilltakealmostafulldaytogetthemachinereadyforaproductionrun,atacostof$300.Inventoryholdingcostswillbe$10perunitayear.Whatrunquantityshouldbeusedtominimizetotalannualcosts?Whatisthelengthofaproductionrunindays?Duringproduction,atwhatratewillinventorybuildup?Ifthemanagerwantstorunanotherjobbetweenrunsofthisitem,andneedsaminimumof10dayspercyclefortheotherwork,willtherebeenoughtime.46Examples AcompanyisabouttoExamples Amail-ordercompanyuses18,000boxesayear.Carryingcostsare20centsperboxperyear,andorderingcostsare$32perorder.Thefollowingquantitydiscountisavailable.Determine:Theoptimalorderquantity.Thenumberofordersperyear.47Examples Amail-ordercompanyExamples Ajewelryfirmbuyssemi-preciousstonestomakebraceletsandrings.Thesupplierquotesapriceof$8perstoneandquantitiesof600stonesormore,$9perstoneforordersof400to599stones,and$10perstoneforlesserquantities.Thejewelryfirmoperates200daysperyear.Usagerateis25stonesperday,andorderingcostis$48perorder.

A. Ifcarryingcostare$2peryearforeachstone,findtheorderquantity thatwillminimizetotalannualcost. B. Ifannualcarryingcostare30percentofunitcost,whatistheoptimal ordersize? C. Ifleadtimeissixworkingdays,atwhatpointshouldthecompany reorder?48Examples AjewelryfirmbuyssExamples

Thehousekeepingdepartmentofamotelusesapproximately400washclothsperday.Theactualamounttendstovarywiththenumberofguestsonanygivennight.Usagecanbeapproximatedbyanormaldistributionthathasameanof400andastandarddeviationof9washclothsperday.Alinensupplycompanydeliverstowelsandwashclothswithaleadtimeofthreedays.Ifthemotelpolicyistomaintainastockoutriskof2percent,whatistheminimumnumberofwashclothsthatmustbeonhandatreorderpoint,andhowmuchofthatamountcanbeconsideredsafetystock? Themotelintheprecedingexampleusesapproximately600barsofsoapeachday,andthistendsnottovarybymorethanafewbarseitherway.Leadtimeforsoapdeliveryisnormallydistributedwithameanofsixdaysandastandarddeviationoftwodays.Aservicelevelof90percentisdesired.FindtheROP.49Examples ThehousekeepingdepaExamples

Adistributoroflargeappliancesneedstodeterminetheorderquantitiesandreorderpointsforthevariousproductsitcarries.Thefollowingdatareferstoaspecificrefrigeratorinitsproductline: Costtoplaceanorder: $100 HoldingCost: 20percentofproductcostperyear. Costofrefrigerator: $500each. Annualdemand: 500refrigerators. Standarddeviationduringleadtime: 10refrigerators. Leadtime: 7days. Consideranevendailydemandanda365-dayyear. A.Whatistheeconomicorderquantity? B.Ifthedistributorwantsa97%serviceprobability,whatreorderpointRshouldbeused? Whatisthecorrespondingsafetystock? C.Ifthecurrentreorderpointis26refrigerators,whatisthepossibilityofstock-out?

50Examples AdistributoroflargExamples Alocalservicestationisopen7daysaweek,365daysperyear.Salesof10W40gradepremiumoilaverage20cansperday.Inventoryholdingcostsare$0.50precanperyear.Orderingcostsare$10perorder.Leadtimeistwoweeks.Backordersarenotpractical--themotoristdrivesaway. A. Basedonthesedata,choosetheappropriateinventorymodeland calculatetheeconomicorderquantityandreorderpoint.(Demandis deterministic). B. Thebossisconcernedaboutthismodelbecausedemandreallyvaries. Thestandarddeviationofdemandwasdeterminedfromadatasample tobe6.15cansperday.Themanagerwantsa99.5%service probability.Determinethenewreorderpoint?UseQoptfromPart-A.

51Examples AlocalservicestatiExamples Asmallcopycentreusesfiveboxesofcopypaperaday.Eachboxcontains10packagesof500sheets.ExperiencesuggeststhatusagecanbewellapproximatedbyaNormaldistributionwithameanoffiveboxesperdayandastandarddeviationofone-halfboxperday.Twodaysarerequiredtofillanorderforpaper.Orderingcostis$10perorder,andannualholdingcostis$10perboxperyear.Determinetheeconomicorderquantity,assuming250workdaysayear.Ifthecopycenterreorderswhenthesupplyonhandis12boxes,computetheriskofastockout.Iffixedintervalofsevendays,insteadofROP,isusedforreordering,whatriskdoesthecopycenterincurthatitwillrunoutofstationerybeforethisorderarrivesifitorders36boxeswhentheamountonhandis12boxes?52Examples AsmallcopycentreuExamples RegionalSupermarketisopen360daysperyear.Dailyuseofcashregistertapeaverages10rolls.UsageappearsNormallydistributedwithastandarddeviationof2rollsperday.Thecostoforderingtapeis$5perorder,andcarryingcostsare40centsperrollayear.Leadtimeisthreedays.WhatistheEOQ?WhatROPwillprovidealeadtimeservicelevelof96percent?Whatistheexpectednumberofunitsshortpercyclewith96percentservicelevel?Peryear?Whatistheannualservicelevel?53Examples RegionalSupermarketExamples Adepotoperates250daysayear.DailydemandfordieselfuelatthedepotisNormalwithanaverageof250litersandastandarddeviationof14liters.Holdingcostforthefuelis$0.30perliterperyear,anditcosts$10inadministrativetimetosubmitanorderformorefuel.Ittakesonedaytoreceiveadeliveryofdieselfuel.CalculatetheEOQ.Determinetheamountofsafetystockthatwouldbeneededifthemanagerwants.Anannualservicelevelof99.5percent.Theexpectedamountoffuelshortperordercycletobenomorethan5liters.54Examples Adepotoperates25055写在最后成功的基础在于好的学习习惯Thefoundationofsuccessliesingoodhabits55写在最后成功的基础在于好的学习习惯谢谢聆听·学习就是为了达到一定目的而努力去干,是为一个目标去战胜各种困难的过程,这个过程会充满压力、痛苦和挫折LearningIsToAchieveACertainGoalAndWorkHard,IsAProcessToOvercomeVariousDifficultiesForAGoal谢谢聆听LearningIsToAchieveACInventoryManagementChapter1257InventoryManagementChapter12IndependentandDependentDemandDependentDemandUsedintheproductionofafinalorfinishedproduct.Isderivedfromthenumberoffinishedunitstobeproduced.E.g.ForEachCar:4-wheels.Wheelsarethedependentdemand.IndependentDemandSoldtosomeone.Precisedeterminationofquantityimpossibleduetorandomness.Forecastingthenumberofunitsthatcanbesold.FocusonmanagementofIndependentDemandItems.58IndependentandDependentDemaTypesofInventory

RawmaterialComponentsWork-in-progressFinishedgoodsDistributionInventoryMaintenance/repair/operatingsupply(MRO)59TypesofInventoryRawmateriTomeetanticipateddemand.Tosmoothproductionrequirements.Todecoupleoperations.Toprotectagainststockouts.Totakeadvantageofeconomiclotsize.Tohedgeagainstpriceincreasesortotakeadvantageofquantitydiscounts.FunctionsofInventory60Tomeetanticipateddemand.FunObjectivesofInventoryControlInventoryManagementhastwomainconcerns:LevelofCustomerService.Costoforderingandcarryinginventories. Achievesatisfactorylevelsofcustomerservicewhilekeepinginventorycostswithinreasonablebounds.2fundamentaldecisions:

--TimingofOrders--SizeofOrdersMeasuresofeffectiveInventoryManagement:CustomerSatisfaction.InventoryTurnover=COGS/AverageInventory.DaysofInventory:expectednumberofdaysofsalesthatcanbesuppliedfromexistinginventory.

i.e.whent