最新小明的一天课件PPT.ppt 65页

'小明的一天 猜一猜儿歌：滴嗒滴嗒，滴嗒滴嗒，铛铛铛……滴嗒滴嗒，滴嗒滴嗒，铛铛铛……会走没有腿，会说没有嘴，它会告诉我们，什么时候起，什么时候睡。猜猜这是什么？钟表 各式各样的钟表 指针式数字式 121234567891011钟面通过观察你发现了钟面上有什么？长又细的是分针12个数短又粗的是时针分针时针 121234567891011钟面12个数怎么排列呢？12693 1278910111234561278910111234569时4时半写作：9:004:30 小明的一天 7时 8时 9时半 12时 4时 8时半 8时8：007时7：009时半9：304时4：008时半8：3012时12：00 8时8：007时7：004时4：0012时12：00整时分针指着12，时针指着几就是几时！ 9时1278910111234561278910111234562时1.说出钟面所表示的时间。 9时半9：308时半8：30半时分针长长指着６，半时：（走过几，必须到两个数的中间）时针走过几，就是几时半！ 1278910111234561278910111234562时半10时半说出钟面所表示的时间。 127891011123456127891011123456拨一拨7时半12时半 游戏：你说我拨游戏规则：同桌互相合作。先左边同桌说几时，右边同桌拨。交换进行。 小明的一天安排真合理。 1.认一认 3时3：003时半3：305时5：006时半6：30 2.连一连 TheNewsvendorModel报童模型 “Toomuch”and“toolittle”costsCo=overagecostThecostoforderingonemoreunitthanwhatyouwouldhaveorderedhadyouknowndemand.Inotherwords,supposeyouhadleftoverinventory(i.e.,youoverordered).Coistheincreaseinprofityouwouldhaveenjoyedhadyouorderedonefewerunit.Cu=underagecostThecostoforderingonefewerunitthanwhatyouwouldhaveorderedhadyouknowndemand.Inotherwords,supposeyouhadlostsales(i.e.,youunderordered).Cuistheincreaseinprofityouwouldhaveenjoyedhadyouorderedonemoreunit. BalancingtheriskandbenefitoforderingaunitOrderingonemoreunitincreasesthechanceofoverage…ExpectedlossontheQthunit=CoxF(Q)F(Q)=Distributionfunctionofdemand=Prob{Demand<=Q)…butthebenefit/gainoforderingonemoreunitisthereductioninthechanceofunderage:ExpectedgainontheQthunit=Cux(1-F(Q))Asmoreunitsareordered,theexpectedbenefitfromorderingoneunitdecreaseswhiletheexpectedlossoforderingonemoreunitincreases. NewsvendorexpectedprofitmaximizingorderquantityTomaximizeexpectedprofitorderQunitssothattheexpectedlossontheQthunitequalstheexpectedgainontheQthunit:Rearrangetermsintheaboveequation->TheratioCu/(Co+Cu)iscalledthecriticalratio.（临界比或关键比例）Hence,tomaximizeprofit,chooseQsuchthatwedon’thavelostsales(i.e.,demandisQorlower)withaprobabilitythatequalsthecriticalratio TheNewsvendorModel:Performancemeasures绩效指标 NewsvendormodelperformancemeasuresForanyorderquantitywewouldliketoevaluatethefollowingperformancemeasures:Expectedlostsales（期望销售损失）TheaveragenumberofunitsdemandexceedstheorderquantityExpectedsales（期望销售）(comparedtoexpecteddemand)Theaveragenumberofunitssold.Expectedleftoverinventory（期望售后剩余库存）Theaveragenumberofunitsleftoverattheendoftheseason.ExpectedprofitExpectedfillrate（期望订单完成率）ThefractionofdemandthatissatisfiedimmediatelyIn-stockprobability（存货满足概率）ProbabilityalldemandissatisfiedStockoutprobability（缺货概率）Probabilitysomedemandislost formulaExpectedsales=m-Expectedlostsalesm:ExpecteddemandL(z):lossfunction(标准正态)损失函数,随机变量超过一个固定值的期望值之和。ExpectedLeftOverInventory=Q-ExpectedSales formulaIn-stockprobability=F(Q)=Φ(z)Stockoutprobability=1–F(Q)=1–In-stockprobability TheNewsvendorModel:Thetargetin-stockprobabilityandthetargetfill-rateobjectivesforchoosingQin-stockprobability：缺货情况，对杂货店较重要fill-rate：多少顾客满足的情况，对目录零售商较重要 ChooseQsubjecttoaminimumin-stockprobabilitySupposewewishtofindtheorderquantityfortheHammer3/2thatminimizesleftoverinventorywhilegeneratingatleasta99%in-stockprobability.Step1:Findthez-statisticthatyieldsthetargetin-stockprobability.IntheStandardNormalDistributionFunctionTablewefindF(2.32)=0.9898andF(2.33)=0.9901.Choosez=2.33tosatisfyourin-stockprobabilityconstraint.Step2:Convertthez-statisticintoanorderquantityfortheactualdemanddistribution.Q=m+zxs=3192+2.33x1181=5944 ChooseQsubjecttoaminimumfillrateconstraintSupposewewishtofindtheorderquantityfortheHammer3/2thatminimizesleftoverinventorywhilegeneratingatleasta99%fillrate.Step1:Findthelostsaleswithastandardnormaldistributionthatyieldsthetargetfillrate.Step2:Findthez-statisticthatyieldsthelostsalesfoundinstep1.FromtheStandardNormalLossFunctionTable,L(1.53)=0.0274andL(1.54)=0.0267Choosethehigherz-statistic,z=1.54Step3:Convertthez-statisticintoanorderquantityfortheactualdemanddistribution.Q=m+zxs=3192+1.54x1181=5011 讨论不足成本大时（毛利高），订购量大于期望需求（关键比例大于0.5）；反之相反。剩余成本可能是可见成本，而销售损失是机会成本，在报表中看不到。剩余成本可能是积压的库存，如未及时清理，造成虚假利润除了利润最大化目标外，很多情况下会选服务水平目标，因为要考虑长期效应。 Assemble-to-order,make-to-orderandQuickResponsewithreactivecapacity按订单装配、按订单生产和以反应性能力快速响应 Thedemand-supplymismatchcostDefinition–thedemandsupplymismatchcostincludesthecostofleftoverinventory(the“toomuch”cost)plustheopportunitycostoflostsales(the“toolittle”cost):Themaximumprofitistheprofitwithoutanymismatchcosts,i.e.,everyunitissoldandtherearenolostsales:ThemismatchcostcanalsobeevaluatedwithMismatchcost=Maximumprofit–Expectedprofit Whenisthemismatchcosthigh?Mismatchcostasapercentofthemaximumprofitwheref(z)=densityfunctionoftheNormaldistribution(InExcelf(z)=normdist(z,0,1,0))Themismatchcostishighwhen(f(z)/F(z))and(s/m)arehigh. LowcriticalratioshighmismatchcostsThemismatchcostishighwhen(f(z)/F(z))ishigh……(f(z)/F(z))ishighwhenthecriticalratioislow: 变差系数反映预测质量，提高预测精确性，可有更高利润。关键比例小的产品，剩余成本高，容易过时的和容易腐败的产品采购少。若残值为零，关键比例即为毛利率，故食堂原材料备料库存少（毛利低，积压成本大），餐厅备料较充分，过期库存多。 不同的不匹配成本与运营管理模式MTS—报童模型不匹配成本为过量或不足，MTS适合于关键比例高、需求变动小MTO—排队系统不匹配成本为生产闲置、顾客排队MTO适合于短途运输、短提前期、机器或劳动力便宜中间状态为使用反应性能力进行快速响应两种反应性能力：第二次订购能力无限但较第一次订购昂贵的反应性能力第二次订购能力有限的反应性能力 SomeU.S.airlineindustryobservationsSincederegulation(1978)137carriershavefiledforbankruptcy.From95-99(theindustry’sbest5yearsever)airlinesearned3.5centsoneachdollarofsales:TheUSaverageforallindustriesisaround6cents.From90-99theindustryearned1centper$ofsales.Carrierstypicallyfill72.4%ofseatsandhaveabreak-evenloadof70.4%. MatchingsupplytodemandwhensupplyisfixedExamplesoffixedsupply:Travelindustries(fixednumberofseats,rooms,cars,etc).Advertisingtime(limitednumberoftimeslots).Telecommunicationsbandwidth.SizeoftheMBAprogram.Doctor’savailabilityforappointments.Revenuemanagementisasolution:Ifadjustingsupplyisimpossible–adjustthedemand!Segmentcustomersintohighwillingnesstopayandlowwillingnesstopay.Limitthenumberofticketssoldatalowprice,i.e.,controltheaveragepricebychangingthemixofcustomers. RevenuemanagementandmarginarithmeticSmallchangesinrevenuecanhaveabigimpactonprofit,especiallyforhighgrossmarginandlownetprofit%industries: EnvironmentssuitableforrevenuemanagementThesameunitofcapacity(e.g.,airlineseat)canbeusedtodeliverservicestodifferentcustomersegments(e.g.,businessandleisurecustomers)atdifferentprices.Highgrossmargins(sothatthevariablecostofadditionalsalesislow).Perishablecapacity(itcannotbestored)andlimitedcapacity(allpossiblecustomerscannotalwaysbeserved).Capacityissoldinadvanceofdemand.Thereisanopportunitytosegmentcustomers(sothatdifferentpricescanbecharged)anddifferentsegmentsarewillingtopaydifferentprices.Itisnotillegalormorallyirresponsibletodiscriminateamongcustomers. RevenueManagement:Bookinglimitsandprotectionlevels预定限额和保留水平 PracticalproblemTheParkHyattPhiladelphiaattheBellevue.118King/Queenrooms.HyattoffersarL=$159(lowfare)discountfareforamid-weekstaytargetingleisuretravelers.RegularfareisrH=$225(highfare)targetingbusinesstravelers.Demandforlowfareroomsisabundant.LetDbeuncertaindemandforhighfarerooms.SupposeDhasPoissondistributionwithmean27.3.Assumemostofthehighfare(business)demandoccursonlywithinafewdaysoftheactualstay.Objective:Maximizeexpectedrevenuesbycontrollingthenumberoflowfareroomsyousell. YieldmanagementdecisionsThebookinglimitisthenumberofroomsyouarewillingtosellinafareclassorlower.Theprotectionlevelisthenumberofroomsyoureserveforafareclassorhigher.LetQbetheprotectionlevelforthehighfareclass.Qisineffectwhileyouselllowfaretickets.Sincethereareonlytwofareclasses,thebookinglimitonthelowfareclassis118–Q:Youwillsellnomorethan118-Qlowfareticketsbecauseyouareprotecting(orreserving)Qseatsforhighfarepassengers.0118QseatsprotectedforhighfarepassengersSellnomorethanthelowfarebookinglimit,118-Q TheconnectiontothenewsvendorAsingledecisionismadebeforeuncertaindemandisrealized.Thereisanoveragecost:IfDQthenyouprotectedtoofewrooms(youunderprotected)……sosomeroomscouldhavebeensoldatthehighfareinsteadofthelowfare.ChooseQtobalancetheoverageandunderagecosts. OptimalprotectionlevelOveragecost:IfDQweprotectedtoofewrooms.D–Qroomscouldhavebeensoldatthehighfarebutweresoldinsteadatthelowfare,soCu=rH-rLOptimalhighfareprotectionlevel:Optimallowfarebookinglimit=118–Q*ChoosingtheoptimalhighfareprotectionlevelisaNewsvendorproblemwithproperlychosenunderageandoveragecosts. HyattexampleCriticalratio:Poissondistributionwithmean27.3:Answer:24roomsshouldbeprotectedforhighfaretravelers.Similarly,abookinglimitof118-24=94roomsshouldbeappliedtolowfarereservations. RelatedcalculationsHowmanyhigh-faretravelerswillberefusedareservation?Expectedlostsales=4.10.Howmanyhigh-faretravelerswillbeaccommodated?Expectedsales=Expecteddemand-Lostsales=27.3-4.1=23.2Howmanyseatswillremainempty?Expectedleftoverinventory=Q-Expectedsales=24-23.2=0.8.Whatistheexpectedrevenue?$225xExp.sales+$159xBookinglimit=$20,166.Note:withoutyieldmanagementworstcasescenariois$159x118=$18,762. RevenueManagement:Overbooking Uglyreality:cancellationsandno-showsApproximately50%ofreservationsgetcancelledatsomepointintime.Inmanycases(carrentals,hotels,fullfareairlinepassengers)thereisnopenaltyforcancellations.Problem:thecompanymayfailtofilltheseat(room,car)ifthepassengercancelsattheverylastminuteordoesnotshowup.Solution:sellmoreseats(rooms,cars)thancapacity.Danger:somecustomersmayhavetobedeniedaseateventhoughtheyhaveaconfirmedreservation. Hyatt’sProblemTheforecastforthenumberofcustomersthatdonotshowup(X)isPoissonwithmean8.5.Thecostofdenyingaroomtothecustomerwithaconfirmedreservationis$350inill-willandpenalties.Howmanyrooms(Y)shouldbeoverbooked(soldinexcessofcapacity)?Newsvendorsetup:Singledecisionwhenthenumberofno-showsinuncertain.UnderagecostifX>Y(insufficientnumberofseatsoverbooked).OveragecostifXYthenwecouldhavesoldX-Ymorerooms……tobeconservative,wecouldhavesoldthoseroomsatthelowfare,Cu=rL.Overagecost:ifX