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The JapaneseTheJapanese AssooiationAssociationofofManagementManagement AooountingAccounting日本 管 理 会 計 学 会 誌管 理 会 計 学 20（n 年 第 13巻 第 1論・2号（合併 号）文Estimatingthe maintenanceAcalculationcase：of automobileVitoon Puripunyavanichin LifeCycle Costownershipin the U ．S ．and repair costSatoshiMyojoYuichiroKanazawaAbstractThe maintenanceand repair cost of dulablegoodShas traditionallybeen hidden from consumersandyeIhas been non negiigible p rt of Life Cycle Cosl （LCC ）computation ． PrediCtingthe maintenanceandrepaircost is diff三Gult because manyof thesedulablegoods do not have constant fanure Tates ． For ��haveat藍eastaroughideaastotheirreliabi置ity． InproducIsthis studywea methodto convertautomobilereliability data 孟n the U ．S ．！o theirpropose and illustratemonetarymaintenanoeand repair cost ． In our metho4 we firslestimate a staI重sticalmodcl from the widelyavailablereliabilitydata． Then we predictthe reliabi 玉ityfromthe nodeLFinallywe convert 重he predictedreliability10 cost figtlles． Tbe proposedstatistical model takes care of the possiblebias introducedbymissing reliabilitydata． Conversion to cost figureisdone on 1he twenty six 1996 model yearpartiallyvehicles popularinIhe U ．S．during1992 1999 ，盆，［K 画yWordsLife Cycle Cost； Reliabilityof A ロtomobile ； Nonignorable Nonresponse ；Multinornial LogisticRegressionModelラ イ フ サ イ クルコスト算 出 に お け る 維 持 お よ び 修 理 費 用 の 推 定ア メ リカ で の自動車 所 有 の 例Vitoon Puripunyavanichく論 文趣 旨〉これ ま で 耐 久消 費 財 の 維 持 お よび 修 理 に か か る費 用 に 関 し て は，金 澤雄 一 郎明城 聡ラ イ フ サ イ クルコ スト計 算 に おた ．一定も無視 で き な い 費 用 で あ る に もか か わ ら ず消費者 は あ ま り知 らさ れ て こ な か っの故 障つ い て そ の 維持 お よ び 修 理 費用 を 推 定 す る こ と は 困 難 で あ る ．しか し な が ら例 え ば 自動 車 の よ う な 財 に つ い て は少 な く と も そ の 信 頼性 に 関 して は 大 ま か に では あ る が 情報 を得 る こ とが で きる 。そ こ で 本研 究 で は ア メ リ カ 自動 車信頼性 デ ー タ か ら維 持 ・修 理こ の 方 法 で は まず 広 く利 用 可 能 な 信頼性 デ ー タ か ら統 計 的 モ デ費 用 を算 出方 法 に つ い て 提 案 す る ．ル を推定 す る ．そ し て モ デ ル か ら推 定 さ れ る 自動 車 の 信 頼 性 か ら費 用 へ 変換 を行 う ，こ こ で 用 い る統計的 モ デ ル で は 部 分 的 に 欠損 して い る 信 頼 性 デ ー タ か ら起 こ り う る 偏 りの 問 題 に 対処 す る こ とを 可 能 に して い る ．具 体 的 な 費 用 算 出 例 と して 1996年 モ デ ル イ ヤ ー に お い て 人 気 の あ っ た 26車 種 を取 り上 げ た ，い て頻 度 を 持 た な い 多 くの 耐 久 消 費 財 に，〈キー ワ ー ド〉ラ イ フ サ イ ク ル コ ス2003年 3 月 26 日2004年 3 月 30 日ト，自動 車 信 頼 性，無視 できな い 非応答，多項ロ ジス テ ィック回帰 モ デルSubmitted26 ，March 2003 ．Accepted 30，March 2004．Universityof Tsukuba受付受理筑 波大学3一NNII-Electronic工 工 EleotronioLibraryLibraryService

The JapaneseAssociationTheJapanese AssociationofofManagementManagement AccountingAccountingWmpftat7 ig13tsag1･2t (al#g)1IntroductionTheL cost"purchase, Forin theproduct forconsurnersof acaseproductaConsumersthemselves have become increasinglyawarewithuse,(EPCA) ofConservation Actconsumptionalso(DOT)Forincluded aC corporateforeachexarnple,fortheaMailabledurab!e productsgasolinemotorexpenditureet ai.newEnergyanewDepartmentof Ttansportafornew car starting in modelof settingup'wasoil andothervehiclefueleconomyand'IltielEconomy Guide asBy lookingat the'aidea onpretty goodwindow-stickersthe averageestimateandis withoutdoubt the mostonto 6,358 or 17.06%'acquisitionthe averageandSurvey,does notyeaily nmentstatecestandresponsibilityto theCivilCode vehic]ehouseholdaveragebefore the ' timeof nnerhave at leastsevenchoice.totheestimatethe Lemon LawsasmoreUntil nowrepairProtectionAct) isoneyears to thinkaboutcarsuchare expectedfrom onemodeithere has been nooftheautomobile.tomanufacturersCaliforniaLemon Law - CAAlthough the ed.in their firstyear ofandcanin the U.S. Consumer Expenditureof consumer;soMceofConsumer Union.as'because it variesautomobileforexample,product theytheGuide, tLaws likethis one are protectingconsumerstyplcal consumersfotanyto the particular automobileapplyrequiringthe FUel EconomyusingIt is diMcult,however,to predictrepairregulationanper gallon(mpg)of inilespurchase from the sticker price and price quetationservices frem such organizationsto anotherstan-have been provided by the EPA.estimatesamounted(EPA) 37,260,ofConsumers tend to haveto roughlystandard,National Vehieleand FUel EmissionsThe Guide Iistsestimatesexpensesthe'(DOE)to publishthecar,to meetrequiredfederalemissionswithpurchase, automobileconsurnersstandard'year. Thesemodelcost1980).put Environmental Protection Agencycomplianceofbut theto discloseenergy'to the U,S. Consumer Expenditure Surveyin e purchase ofconsideringvehicleallexample,has been y"The programdaTds. The prograrri asked DepartmentOfForthe cost of acquiringonlyin 1979. Each autornakerstartingfueleconomyLaboratory tQ determine carto consumgrshomeaskingaverageto 1arge finesfor non-compliance.of measuringnotAuto Fuel Economy Program," in which"Newyear 1978,and fbrnew lighttrucksforeachthe time ofthe U.S. government, through the Energy Policy andexample,1975, has beendirectedto setwasin chargeoftheirproducts (McNeillet al. 1979, HuttononThe EPCAsubjectbd quite misleading.disposalof the durableproducts.Thisandmaintenancetranslatedinto the U,S, regulations.tionatdurablegoods, significant cost will be incurredin the use and maintenanceof thewhichincludesall the costs associatedperiod of years. Life CycleCost (LCC),withmaintenance,anddisposal,is more reasonable alternativeto evaluate such tion,equatedof cost canproducts, however, this definitionsomeofhas traditionally beenrepairthroughout the country,cost,because"themedian4NII-Electronic Library Service

The JapaneseAssociationTheJapanese AssociationofofManagementManagement AccountingAccountingEstimating themalntenance-Aageofcarstheoncasein 1999 is moreroadferthe frequencyoftillustratea methedandInofdatabasesmaintainabilityto have constantthe oftenasofmodeltheof non-electronicandreliabilityConsumer Reportsasandcost ofatorepair1979, abilityfailureratesanuschoicecostconsideredthe mathernatics(MTTR),andlead tocancomputerizeddiMcult to ebtainonlyusagerepairare'leavingof autprnobiles,thetime to repairmeanit verytcost."thtough the1983), willcomponentshave non-constantcomponentswefor this is the factthatreason1999(Aprilcan :monetary'generalproduct isestimatedTheorIn this papermodel.time befbre failure(MTBF) andmeanbe,have significantthey maysuchmake!981).(Taylorto intractable mathematicsthe unwaryspecificrepair:6} years in ile most electronic- which ratesfor calculatingin Life Cycle Costin the U.S.-costownershipknowledgeof the' frequencyofandopinionsprofessionalanddepends o convertrepairthan 8 years,Consumer Reports page 97), Public cantheir websiteandef automobiletheoreticalof statisticalmethodfortracing them.Ourfivepointandisas follows:We tedtheestimatescorereliabilityfrom the thirty best-sellingpassengercarsandvehiclesperiod.Since these popular fiftyandcoveredconsumers,al] ion4weintomodelasdiscusstheweonsources.in U,S. , and pickup trucksthe best-sellinglistthroughout73.1% ofcoveredSUV,calculatedmethodsusecldescribedin sectionAppendix Aresult.B descrlbesin detai1howtheir siblingscar, minivan,foIlows.Thefigure arecostandconsistentlyfrom the rnodel,the data frotnseveralthe twenty thein 1996soldpickup truck-important to averageandisrepresentative,choiceThis paper is organizedmaintenanceof automobilebecausethey arepredictthereliabilityin their firsteight years ofandin the United States during 1992-1999weto cost figureusingvehicle-specifictwenty-six popular hoosethe reliabilityregressingmodelpublished in the Consumer Reports onscaleto buyers thinking of purchasinga newaNailablestatisticalatheexp]ains2, Inhowvehicle-specificin estimatingwe3, thesectionestimatedratiothe statistical modelresultis presented,the statistical cost.2MethodsMaintenanceandcostrepair1, Yearly clataonaveragebymodelcostandyear were in generalnotfor twehaveinsteadare;consumersfrom theConsu7ner EupenditureSurveyi2. Estimates of CtypicaV'itemizedmaintenanceandrepaircostby modelfbreightmajormechanical5NII-Electronic Library Service

The JapaneseAssociationTheJapanese AssociationofofManagementManagement AccountingAccountingermpftX\ as13tsag1･2e art ofMechanical PartsevLabor Estimatingfrom thtchellcompiledislistedin thble 1;which'Table1: Subsystemand alincludinglabor and theirsystemsfor 1996-model-yearvehicles in 1999.Ford TaurusMajor SystemSubsystemA!CBlower Heater CoreCemp:e sorHondaAccordTbyota･･,Camry 461 973 551 559 1,020 594 1,567 SS6 1,437･･･[[btalReHabi]ityCooiing4Water Pump54 260 671 e31 408 383 T91 324 55S 8S2RadiatDr Hose･･･TetalReliabilityElectricalWindew25 150 148 298Motor5 182 265 447 316 240 556Wiper respondingAugst 2000 issueConsumeref3. Desigricharacteristicsof 1996-model-year vehiclesReportstheirandweresaleslisted.data from WbTzi'sAutomotiveM7arbooksin 1996 and 1997;4. The total numberof up-to-eight-year-oldof onvehiclesthe road in 1999 from Ward lsMotor Vbhiclethcts and Figures in 2000 in Figure 2;'5. The likelihoodsof problems in eachofthe l from April 1997-2002 Consumer ewill userepairnumberthesedatato constructcosttheyonarereliable.solicitedestimatesa carefu11yofvehiclesHowever esigncharacteristicsandof odel-year vehiclesestimatesbyfor1996-vehicle.penditure Survey isbasedandthein April 1993-2002 Consumer Reports. Table 2 is thecategoriesmodel-yearofinto five(threein April 2000 issuefrom April 1997-2002 Consumer Reportslcategories7, Annual (1992-2001)estimatesis alsolistedin Table 1;'which6. Annual (1996-2001)Classificationsof 1996-model-yearyehiclesbetweenefthe estimates1996-model-yearvehiclesof onsamplesandontheroadwhichis basedreliabilityby Consumer Reports.ItseemsonofThe Consumer E!v-cost.itemizedmaintenance"typical"data, and the totalare rsdata, Thesearemaybased areof unreliabrebe presumedselfselected:automobilesare6NII-Electronic Library Service