Market-Sizing案例

MarketSizing案例解答：题目一：请估算中国一年生产的高尔夫球数目解答：高尔夫球数目=50TierOneorTwoCity*20GolfCourts*300Days*GolfBallsUsedTimesEveryday*DepreciationRateGolfBallsUsedTimesEveryday=(200meters*200meters)/(50meters*50meters)*6timesperHours*8Hours其中(200meters*200meters/50meters*meters)为PeopleCapacityDepreciaitonRate=1/20，即使用20次损坏或丢失答案约为1000万个题目二：请估算北京的加油站数目解答：北京的加油站数目=北京的汽车数目*每天加油的次数/每个加油站一天的服务数目北京的汽车数目=北京人口（=2000万）*20-50岁人口比例（=1/2）*月收入大于5000比例（1/10）/私车所占比例(=50%)每天加油的次数=1/每隔多少天加一次油（=10天）每个加油站一天的服务数目=12Hours*60Minutes/10Minutes*3个加油口答案约为1000个题目三：请估算此时此刻中国大陆上空的飞机数目解答：中国大陆上空的飞机数目=中国飞机的数目*一架飞机在空中的概率中国飞机的数目=50TierOneorTwoCity*机场每天吞吐量（即起飞降落数目）/一架飞机一天的起降数目假设此时此刻在白天，则：一架飞机在空中的概率=飞行时间/（飞行时间+整修时间）=2/3机场每天吞吐量（即起飞降落数目）=一分钟的起降数（=20分钟起降/20个跑道）*12Hours*60Minutes一架飞机一天的起降数目=二到三个航班*2=5（包含国际航班影响的平均值）答案约为1万架Duringyourcaseinterview,youmaybeaskedtomakeestimatesorsolveaproblem.You'llfindtwoexamplesbelowthatwillhelpyouthinkthroughtheprocessofarrivingatreasonableestimates.Thethirdquestionisabrainteaser—aremindertothinkcreativelywhentacklinganycaseinterviewproblem.Q:HowmanypayphonesarethereontheislandofManhattan?A:AlogicalplacetobeginyouranalysismightbetoballparkthenumberofpayphonesonManhattanstreetcorners.IfyouthinkofNewYorkCityasagridofstreets,youmightguessitisabout300streetslong(northtosouth)bytenstreetswide(easttowest),soithasapproximately3,000intersections.Youmightthenassumethereisonepayphoneforeverytwointersections,foratotalofabout1,500payphones.Ifyou’refeelingreallycreative,youmightsubtractthenumberofintersectionsthatare“invalidated”becausetheyfallintheareaofCentralPark.SayCentralParkistenblockslongbytwoblockswide,or20intersections.Usingyourone-pay-phone-for-every-two-intersectionsassumption,youwouldwanttosubtracttenpayphonesfromtheoriginal1,500.Youmightthenaddtothe1,490thenumberofpayphonesthatmightbefoundinrestaurants,hotels,schools,hospitals,andoffice-buildinglobbies.Q:Howmanyhotel-sizedbottlesofshampooandconditionerareproducedeachyeararoundtheworld?A:Youmightbeginbyassumingthathotel-sizedbottlesareproducedfortwopurposesonly:1.Tosupplyhotelsandupscalemotels2.Toprovidesamplesforgiftpacks,salons,andsoonYouwouldthenwanttostartbyestimatingthenumberofhotelsandmotelsaroundtheworldthatoffertheproductstotheirguests.Onewayofestimatingthenumberofhotelsistoassumethathotelsarefoundpredominantlyinmajorcitiesandresorts.Figurethatthereare2,000majorcitiesandresortsaroundtheworld,anaverageoftenforeachoftheworld’sapproximately200countries.Assumethateachcityaverages20hotelsthatofferbottledhairproductstotheirguests.Multiplying20by2,000givesyou40,000hotelsaroundtheworldthatrequireshampooand/orconditionerfortheirguests.Tounderstandhowmanybottlesofshampooandconditionerthe40,000hotelsrequire,younowneedtoestimatethetotalnumberofuseseachhotelonaveragerepresents.Youcanarriveatthatnumberthroughthefollowingcalculation:assumethatthereare100roomsineachhotel,andthatthoseroomsareoccupied50percentofthetime.Multiplying40,000by100by0.5by365(don’tforgetthenumberofdaysintheyear!)givesyouapproximately750million.However,itisprobablyreasonabletoassumethatagueststayingforlongerthanadaywillnotuseawholeshampoobottleeveryday.Ifyouassumethatanaverageofoneshampoobottleisusedforeverytwooccupieddaysinagivenroom,youcannowdivideyour750millionestimateinhalfto375million.Togettothenumberofbottlesofconditioner,estimatearatiobetweentheuseofshampooandtheuseofconditioner.Sincemanyofusdonotconditioneverytimeweshampoo,youmightassumethattheratiois2:1.Dividing375millioninhalfgivesyouapproximately190million.Yourconclusionwouldthenbethat375millionbottlesofshampooand190millionbottlesofconditionerarerequiredforhoteluseeveryyear.Toestimatethetotalmarketsize,youcanprobablymakethingseasyonyourselfbyassumingthatthenumberproducedforsamplepurposesisasmallpercentageofthetotal,saytenpercent.Combiningyourtwomarketswouldgiveyouapproximately400millionbottlesofshampooand210millionbottlesofconditioner.Finally,youmightwantto“realitycheck”yourtotalfigure.Assuming610millionbottlesareproducedandsoldeachyearatanaveragepriceof25centseach,theworldwidemarketforminiaturebottlesofshampooandconditionerisabout$150million.Doesthatsoundreasonable?Q:Youareinaroomwiththreelightswitches,eachofwhichcontrolsoneofthreelightbulbsinthenextroom.Yourtaskistodeterminewhichswitchcontrolswhichbulb.Alllightsareoff.Yourconstraintsare:youmayflickonlytwoswitchesandyoumayentertheroomwiththelightbulbsonlyonce.Howwouldyousetaboutdeterminingwhichswitchcontrolswhichbulb?A:Tosolvethisriddleyoumustdosomeout-of-the-boxthinking.Thebestwaytodeterminewhichlightbulbiswhichistoflickoneswitchon,waitforfiveminutesandflickitoff.Thenflickoneoftheremainingtwoswitchesonandleavetheotheroff.Whenyouentertheroomwiththebulbs,youcandeterminewhichswitchcontrolswhichofthetwolightsthatareoffbyfeelingtoseewhichofthebulbsishot(fromhavingburnedforfiveminutes).Othercreativesolutionsinvolvepushingtheconstraintsofthegame.Youmightaskiftheroomyou’reinhasaphone,soyoucouldcallsomebodytohelpyou.Youmightaskiftheroomshaveaconnectingwindow.Youmightassumeyoucanleavethefirstroomanumberoftimes,andther