ch6-Accounting-for-materials英语教学课件

Ch6Accountingformaterials材料核算Topiclist

InventorycontrolInventorylevelsEOQ（经济订货量）

EBQ（经济批量）AccountingformaterialsWhat’sinventory?Rawmaterials（原材料）Workinprogress（在产品）Spareparts/consumable(配件、零件)Finishedgoods（产成品）Topic1Inventorycontrol存货控制Inventorycontrolincludes:Theordering,receipt,storingandissuingofinventory.Controllinglevelsofinventory.storemanufacturepurchaseinventoryorderingandpurchasingreceivinggoodsintostorestoringandissuinginventorycontrollinglevelsofinventoryStorespurchasingPurchaserequisition请购单supplierPurchaseorder订货单Deliverynote交货单accountsGoodsreceivednote收货单CostcentreMaterialsrequisitionnote请料单Materialsreturnednote退料单1.1Theordering,receiptandissueofrawmaterialsCopyofPurchaseorder1.2ThestorageofrawmaterialsBincards（货仓卡片、库存记录）Storesledgeraccount（商品分类账）Freeinventory（备用、可用存货）PerpetualinventoryPerpetualinventoryreferstoaninventoryrecordingsystemwherebytherecordsareupdatedforeachreceiptandissueofinventoryasitoccurs.storemanufacturepurchase1.3Inventorycosts存货成本orderingcostsholdingcostsstockoutcostsorderingcosts定购成本Clericalandadministrativecosts行政和管理成本Transportcosts运输成本Productionruncosts(internally)组织生产的成本holdingcosts持有成本DeteriorationCostsofstorageandstoresoperationsInterestchargesInsurancecostsRiskofobsolescencestockoutcosts存货短缺成本LostcontributionfromlostsalesLossofcustomergoodwillExtracostsofurgentorders………Objectiveofcontrollingthelevelsofinventory

Theoverallobjectiveofinventorycontrolistomaintaininventorylevelssothatthetotalinventorycostsisminimized.Topic2inventorylevelsReorderlevelMaximumlevelMinimumlevelAverageinventoryWheninventoriesreachthislevel,anordershouldbeplacedtoreplenishinventories.(1)

Themaximumrateofconsumption(2)

Themaximumleadtime（交货递延时间）Re-orderlevelQ0timeinventory0timeinventory

Lead-time0timeinventory

Lead-timePurchaseearlierRe-orderlevelorderplacedorderarrivedinventoryleveltimeLead-timere-orderlevel=maximumusage×maximumleadtime

Example:Datarelatingtoaparticularstoresitemareasfollows

Averagedailyusage400unitsMaximumdailyusage520unitsMinimumdailyusage180unitsLeadtimeforreplenishmentofstock10to15daysReorderquantity8,000unitsWhatisthereorderlevel（inunits）whichavoidsstockouts?

A5,000

B6,000

C7,800

D8,000Reorderlevel=Maximumusage×Longestleadtime=520×15=7,800unitsMaximumlevel=reorderlevel

-(minimumusage×minimumleadtime)

+reorderquantityMaximumlevelRe-orderlevelorderplacedorderarrivedinventoryleveltimeMaximumLead-timeMinimumLead-timeRe-orderquantityMaximumLevel新订单到达时剩余的存货Thisisawarningleveltosignaltomanagementthatinventoriesarereachingapotentiallywatefullevel.Minimumlevel

=reorderlevel–（averageusage×averageleadtime）MinimumlevelRe-orderlevelorderplacedinventoryleveltimeMaximumLead-timeaverageLead-timeTheorderisnotarrivedyet!Thisisawarningleveltodrawmanagementattentiontothefactthatinventoriesareapproachingadangerouslylowlevelandthatstockoutsarepossible.Bufferinventory

SafetyinventorylevelAverageinventory

=safetyinventory+1/2reorderquantityAverageinventoryRe-orderlevelorderplacedinventoryleveltimeMaximumLead-timeaverageLead-timeTheorderisarrived!经过平均消耗，订单运达时的存货总量Re-orderquantityDatarelatingtooneparticularstoresitemareasfollows:Averagedailyissues=70unitsMaximumdailyissues=90unitsMinimumdailyissues=50unitsLead-timeforthereplenishmentofstock=11to17daysReorderquantity=2,000unitsReorderlevel=1800unitsWhatistheMaximumstocklevel(inunits)forthisstoresitem?

ExampleA2,950B3,100C3,250D3,800Topic3Economicorderquantity(经济订货量)

Whendetermininghowmuchtoorderatatime,anorganisationwillrecognisethat:asorderquantityrises,averagestockrisesandthetotalannualcostofholdingstockrises;asorderquantityrises,thenumberofordersdecreasesandthetotalannualre-ordercostsdecrease.PatternofinventoryXX/2OrderquantityAverageinventory令：CH

=costofholdingaunitofinventoryforatimeperiodCO

=costofplacinganorderD=totaldemandforatimeperiodTOC=totalre-orderingcostTHC=totalholdingcostX=orderquantityaverageinventory=X2则：X2THC=

×CH

numberofordersinaperiod=

DXTOC=×CO

DXlet：Thetotalcost=CC==THC+

TOCX2×CH

×CO

DX+C’=12×CH

(—×CO)

DX2+CH2×CO

DX2—==02D×CO

X2=CHX=2CODCH

CH

=costofholdingoneunitofinventoryforonetimeperiodCO

=costofplacinganorderD=demandduringthetimeperiodThecalculationisbasedoncertainassumptions

constantpurchasepriceconstantdemandandconstantlead-timeholding-costdependentonaveragestockorderingcostsindependentoforderquantityExample:AcompanydeterminesitsorderquantityforacomponentusingtheEconomicOrderQuantity(EOQ)model.WhatwouldbetheeffectsontheEOQandthetotalannualorderingcostofadecreaseintheannualcostofholdingoneunitofthecomponentinstock?EOQTotalannualorderingcostALowerNoeffectBHigherNoeffectCLowerHigherDHigherLowerD

PointLtdusestheEOQmodeltoestablishthereorderquantityforrawmaterialY.Thecompanyholdsnobufferstock.InformationrelatingtorawmaterialYisasfollows:

Annualusage=48,000units

Purchaseprice=￡80perunit

Orderingcosts=￡120perorder

Annualholdingcosts=10%ofthepurchasepriceExample:Calculate:（i）theEOQforrawmaterialY;（ii）thetotalannualcostofpurchasing,orderingandholdingstocksofrawmaterialY.Whattobeawareof

incalculation(1)Relevantcosts（相关成本）

Onlyincludethosecostsaffectedbyorderquantity.Onlyincludethoseholdingcostswhichwilldoubleifyouordertwiceasmuchatatime.Onlyincludethoseorderingcostswhichwilldoubleifyouordertwiceasoften.example

Annualusage=48,000units

Purchaseprice=￡80perunit

Orderingcosts=￡120perorder

Annualholdingcosts

=10%ofthepurchaseprice=￡8perunitAnnualtotalcostsOrderquantity1,20024,000Holdingcost600×812000×8Orderingcost40×1202×120Purchasingcost48000×8048000×80(2)Consistentunits（单位一致）

Ensurethatfiguresinsertedhaveconsistentunits.Annualdemandandcostofholdingaunitforayear.Bothholdingcostsandre-orderingcostsshouldbein￡,orbothinpence.

BulkDiscounts

批量折扣

Whenbulkdiscountsaretaken,pricesreduce,butannualholdingcostswillincreaseifmoreinventoryisorderedatatime.注意relevantcostsexample

Annualusage=48,000units

Purchaseprice1=￡80perunit

Orderingcosts=￡120perorder

Annualholdingcosts=￡8perunitThesupplierhasofferedadiscountof10%if24,000unitsofthematerialareboughtatatime.Purchaseprice2=￡80×90%=￡72AnnualtotalcostsOrderquantity1,20024,000Holdingcost600×812000×8Orderingcost40×1202×120Purchasingcost48000×8048000×72WHATTODO?

Thecommonapproachinvolvesfindingthetotalannualcost（holdingcost,re-orderingcostandpurchasingcost）atthelevelindicatedbytheEOQandatthelevelwherediscountfirstbecomesavailable.

Example:MooreLimiteduses5,000unitsofitsmainrawmaterialpermonth.Thematerialcosts￡4perunittobuy,deliverycostsare￡25perorderandinternalorderingcostsare￡2perorder.Totalannualholdingcostsare￡1perunit.Thesupplierhasofferedadiscountof1%if4,000unitsofthematerialareboughtatatime.

Ifthediscountoffershouldbeaccepted?Topic4Economicbatchquantity

（EBQ）经济批量Whenresupplyisgradualinsteadofinstantaneous,especiallywhenthematerialisproducedinternally.EBQiscalculated.回顾：patternofinventory

WhenresupplyisinstantaneousEBQ(1-D/R)1/2EBQ(1-D/R)EBQMaximuminventorylevelaverageinventoryproductionformaterialconsumptionofmaterialCH