−ノ（）∴−・
JIT Production andItsInfluence
onCostManagementinJapan
by Shin，ichiIno11e＊ ＊＊ ABSTRACT Just−in−Time（JIT）productionhasbeenwidelyprevailingnotonlyin Japanbutalsoalloverthewor・1dItisverysuitableproductionmanage− mentsystem（PMS）intheperiodofhigh−Varietyandlow−VOlumeproduc− tionBut whenitcomestotheresearchonJIT anditsinf’1uence oncostmanagement，eVeninJapan whereJITwas originated and mostwidely
spread，thereareveryfewstatisticalresearchesintoit“Thispaperaims
atfillingupagapintheresear−Chtopic
This paper shows a trend ofinformatization of cost management，
variety of consumer・needs and theirimpacts on production systems， shorteningOftheproductlife−CyCleanditsinfluencceoncostreduction，
majorproblems andtheirtechniques ofcostmanagement，and changing
cost structur・e andinventory assetsin the era of high−Var−iety andlow− volumeproductioninJapan
1．Introduction−p11rpOSeandlimitoftheresearch
Itis a well−known fact that todayJust−in−Time（JIT）production managementsystem（PMS）andtotalqualitycontrol（TQC）asJapanese
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especiallyinthe USA”Foreign COmPanies have been str・iving for・the transfer of the technniques InJapan，WhereJIT and TQC originated，
there are some case studies ofJIT companies，but comprehensive and Statisticalresearchisstillveryfew1）More comprehensive and statistical researches onJIT anditsimpact oncost management are future tasks Inordertofi11upagapmentionedabove，WeWOuldliketoexaminePMSs andtheirinfluenceoncostmanagement
For the convenience ofachievingthis purpose，PMSs canbe divided
into three：job order production systems（JOS），JIT（or Kanban）system， andmaterialsrequir−ementSplanning（MRP）systemJOSisthetraditional SyStemWhichmakesoutproductionorder・Sbasedonquick−decktables（cost tables）andcontroIsproductionprocessesbytheproductionsystems．The
Toyota production system or the Kanban system，Originated from the ToyotaautomobilecompaniesinJapan，andiswidelysprIeadingalloverthe WOrldanditiscalledasJITinforeignCOuntries．JITconsistsoftwomain
＊）ProfessorofAccountingattheFacultyofEconomicsofKagawaUnlversity
＊＊）Thispaperisbasedontheioint−StudywithProfessorKazuoMiuraandProfessor Yoshiho Tanaka，（both Kagawa University）on“Production Method and Cost
ManagementinJapan−ComparisonwithThoseofEuropeanandAmericanCom− panies”andwasfundedbyGrant−in−AidforScientificResearchbytheMinistry
OfEducationinJapanin1986−87Iamindebtedtothoseprofessorsandalsoa11 respondentsofthecompanieswhoarekindenoughtorespondtothequestionnaire
IalsothankMr KennethEJackson，MrJerryCone，MissHirokoAndoandMiss Rieko Kanazawa for their help and assistance Ofcourse erT・OrSin the paper
belongto theauthor 1）OneexceptionisthepaperwrittenbyYasuhirOMondenettitled，‘TheStatus−quO OfIntroductionofJITinJapaneseAutomobile PartSIndustry，（inJapanese）in KoujγOuRbnn（FactoryManagement），SpecialissueofToyota Pr・OductionSys− tem−Industry←WiseCaseStudies，NikkanKougyouShinbunSha，1988 Monden alsoinsistsonthenecessityofcaseresearchesandquestionnairesurVeySOnJIT
in TapanSee Monden Y，LJIT Production System and Cost Accounting／Cost Management−mainlyaCaseofDaihatsuAutomobileCompanyL，’（inJapanese），
JITProductionandItsInfluenceonCostManagementinJapan RlO9∼
concepts，Just−in−TimeandJIDOKA（autonomation）Itsgoalisto“pro− duce the kind of units needed，at the time needed，andin the quantities needed2）”Itisoftencalled‘thepullsystem’“MRPisthesystemwhichhas
beendevelopedbasedonmainLframecomputersintheU・SAlandisalso
widelyspreadinginJapan3）Itisoftencalled‘thepush−SyStem’incontrast Of‘pullsystem’ofJIT
Nowwewouldliketoexaminethecharacteristicsofcostmanagement
pr・OblemsinJapan based on our1987maiトsurVey Of the manufacturing
COmpanieslistedonTokyoStockExchanges．Wearesurethatacompara−
tivestudyofthosethreesystemswi11clarifythecharacteristicsofJITand itsinfluenceoncostmanagement
Inthispaper，theintroductionofcomputersystemsintocostmanage− mentis explainedin the section2，highLVariety andindividuality ofcon・
Sumer needs and theirimpact on production systems are examinedin
SeCtion3，Shorteningofproductlife−CyCleanditsimpactoncostdownare
insection4，COStmanagementprOblemsandtheirtechniquesareinsection
5，andchangingcoststr’uCtureandinventoryassetsarereviewedinsection 64）
2．Infor・mationsystemsforcostmanagement
ReflectingreCentinformatization and systematization，almost allthe
COmpanieshavealreadyintroducedcomputersystems（CSs）inmanagement activitiesanddatabasesystems（DBSs）havebeenalsousedtosomeextent for’businessactivitiesAsar−eSultofthat，CSsandDBSscanbeguessed
tohavebeenrapidlyspreadnotonlyinthefieldsoffinancialaccountingbut
2）DetailsaboutJIT，SeeMonden，Y，7byotaPYOduction5γStem，ⅠIE，1983
3）DetailsaboutMRP，SeeWight，O W，PYOductionandInvento7／y ManLqement the Con4）uおrA鍔CahnersPublishingCompany∴hc，1974
一ノブり 香川大学経済学部 研究年報 30 ヱ990
alsointhose of managerialaccountingThis phenomenon must have effected on the methods ofcost managementCSs and DBSs are the primarygroundworkforpracticingcostmanagementHereweaskedthe
status−quOOfCSsandDBSsforcostmanagementinthecompanies・The
r・eSults ar・ein Table−1Table−1Computersystemsanddatabasesystems
CSs DBSs
Introduced Partly Introduced Planned
TOS 403％ 481％ 28・6％ 39・9％
JIT 463 519 39．6 35 9
MRP 497 416 29．9 44−8
Tota1 451 458 31。1 40，6
IntroducingOfCSsinto cost management canbe summar’ized as fol− lows‘Totallyintroduced’is45．1％and‘partlyintroduced’shar・eS458％ among the whole companies．If we add the above two figures，they become909％，SO almostallthecompaniesuseCSsfor costmanagement
for some way in Japan
Industry−wiseanalysisshowsthatCSsis49。7％inMRP，463％inJIT and40り3％inJOSJudgingfromthefigures，MRPandJIThavecompara−
tivelyadvancedinintroducingCSsthanthoseofJOS
Whenit comes to DBS which ar’e eSSentialfor multiple−uSe Of cost
manag−ementinformation，31．1％ have already used，406％ are now ‘planned’．WecansaythatDBSsforcostmanagementhavebeenusedto SOmeeXtent，butjudgingfromthefigureof’‘planned’，WeCanSuPpOSethat
itwi11dorninatethebusinessworldinJapan
Specifically，JIT shares40％ofintroducingDBSs，butJOS and MRP
TITProductionandItsInfluenceonCostManagementinJapan −111− 1essdevelopedfor・DBSs．Butwecanpredictfromthefigur・eSOf‘planned’ ofthosetwo（JOSandMRP），theysharelargerfiguresanditmeansthatin JOS andMRP，DBSswillberapidlydevelopedfromnowon 3．HigⅠ卜VarietyofconsumerneedsanditsinflllenCeOn productionsystems
In this section，We review the variety andflexibility of production
（prod）systemswhichisanotherpr・emiseforcostmanagement、Herewe dividethepr・Oductionsystemsintofiveaspects；thetechnologicalcharac− teristicsofproduction，Varietyofproducts，thevolumeofproducts，pr・OC− essmanagementandmarketing”Fromthosefivepointsofview，WeWOuld liketoexaminehowthevarietyofprodsystemsdifferamongJOS，JITand MRP First，theresultfromtheviewpointofthetechnologicalcharacteristics isinTable−2AccordingtotheTable，aSSemblyprodsharesnearlyhalfof thetotalcompanies（461％），thesecondisthemechanicalprocessprodand Shares25．5％Thethirdischemicalprocessprodandshar・eS20”0％，Itis SaidthatJapaneseindustrialstructur・eCOnVergeSOntheassemblyprod Table−2 Thetrendofproductionsystem
System Assembly Mechanical Chemical Others
TOS 547％ 302％ 103％ 47％
丁IT 778 111 19 93
MRP 276 264 351 10．9
Tota1 46−1 255 200 84
Whenweseeitfr・OmPMS，aSSemblyprodshares778％anditissaid that thegreater・pOrtion ofJITcompaniesbelongto assembly prodIn JOS，aSSemblyprodholdsthemajority（54．7％），atthesametimemechani−
香川大学経済学部 研究年報 30 J9財
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Calprocess prod also shares30．2％“We can understand theindustrial
StruCtureinJapaniscentered on the assembly prod，but the mechanical
processprodsharestoconsiderableextentinJOS”WhenitcomestoMRP，
themechanicalprocessprodshares351％anditperformsaleadingSyStem inMRPh Butassemblyprodandmechanicalprodalsosharemorethanone
fourthofthecompanies，thereforeproductionsystemshaveawide−Variety inMRP
Next，the variety of productitems which are manufacturedin one COmpanyis reviewedin Tabler3HighLVariety prod shares more than
three fourths（758％）in aii，and we see that the trend ofmostJapanese
COmpanieshasbeenshiftedgreatlytohigh−Varietypr・oduction”Whenwe
See from the point ofPMS，highpvariety productionshares88”9％inJIT
and almost all companies in JTT respond to high-variety marketing and
produce highーVariety products“InJOS and MRP，highrvariety pr・Od Sharesaround75％respectivelyandmediumrvarietyprodshares14”5％in MRPandll”7％inJOS Low−Varietypr’Odsharesll0％inMRP andlO
8％inJOSrespectively
Table−3 ThevarietyofprodtlCtitcms
Items High Medium Low Others
JOS 758％ 117％ 108％ 1−7％
JIT 88．9 3−7 74 0
MRP 746 145 11−0 0
Tota1 758 12．2 110 10
Thir・dly，fromthe aspect ofproductionvolume ofthe major product
manufacturedinacertainperiodinonecompany，thevarietyofvolumeof the ma50r PrOductisinTable−4The variety of product volumein the
wholecompaniesisasfollows；low−VOlumepr・Odshar・eS471％，medium− VOlumeprodis234％andhigh一VOlume prodis26“8％inthe whole com−
JITProductionandItsInfluenceonCostManagementinJapan ∼113r
paniesWecansaythatJapaneseprodiscenter・edonlow−VOlumeprod
Atthesametimehigh−VOlumepr・Odandmedium−VOlumeprodsharearound l／4r’eSpeCtively
Table−4 Thevarietyofproductvolume
Volume Low Medium High Others
554％ 212％ 208％
377 283 3211
416 249 312
Tota1 471 234 268 2−7
According to the detailed analysis by PMS，We Can find thatlow−
VOlumeprodinJOSisespeciallyhigherthanthoseof other・tWOSyStemS anditshares55A％，thereforewecanunderstandthatthelow−VOlumeprbd has been gr−eatly advanced up to the present（Of course this may be
der−ivedfromtheresultsthatlow−VOlumeprodincludesplenty（about30％）
Ofsingleunitorindividualunitprodcompanies）InMRPtherearealot
Oflow−VOlumeprodcompanies（416％）butit alsoincludes31，2％ofhigh−
VOlume prod and249％of mediumrvolume prod companies respectively According1ythereisavarietyofvolumeofproductioninMRPInJIT，
low−VOlumeprodsharesthehighest，buthigh−VOlumeandmediumLVOlume prodshowalsocomparativelyhigherfigur．esThereismuchmor−eVariety
involumeofproductionofJITthanthatofMRP
Fourthlyletuschecktheproductionvolumewhichispr・Oducedatone
shift（time）5）in Table−5In the whole companies，SO Called‘small−lot
prod’，Whichincludessingleunitpr・Od＋mixedprod6）＋lowvolumeprod， 5）Itiscalleda‘lotsize’incaseofnumberora‘batchsize’incaseofquantity
6）‘Mixedproduction’istheproductionmethodwhichcanproduceoneorseveral unitsofhigh−Varietyproducts（productitems）successivelywithasingleproduc− tion processThe typicalmixed production system can be seenin the final assemblyprocess（1ine）ofJapaneseautomobilecompaniessuchasToyota
香川大学経済学部 研究年報 30
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Table−5 Thevar・ietyofIoトSize
LoトSize Single Mixed Small Medium Large Mass−prOd Others
TOS 294％ 160％ 294％ 152％ 82％ 13％
4％丁IT l9
537 31．5 56 56 19 0MRP 145 204 244 22，7 87 76 17
Total 199 226 265 176 81 37 17
Shares nearly seventy percent（690％），thenit can be said thatJapanese
COmpaniesareabletorespondtothevarietyanduniquenessofconsumer needsnotonlyindomesticbutalsointernationalmarketTheycanhave
enoughcapabilitytoproducetheirpr’Oductscopingwiththef1uctuationof market demand smoothlyMedium−lot prod shares17．7％and so called ‘1arge−lot prod’，Whichincludes high−lot prod ＋ mass−prOd，isll．8％ TheirfiguresaremuchsmallerthanthatofsmalトlotprOd
Whenwe review the production volume from the aspect of PMS，in
JOSsingle−lotandsmalトlotprodshare29h4％respectivelyandtheyoccupy thefirstrankMixedpr’Odandmedium−lot pr’Od share160％and15．2％ respectively，andtheyfollownextHigh−lotprodandmass−prOdsharIe8 2％andl3％eachandtheir shar−es ar’e verysmall，As the result of■the
above，inJOS‘smallLlotprod’isconcentr’atedonanditshar’eS74．8％and theprocessmanagementisfocusedon‘small−lotprod’
InJIT，mixed prodshar・eS mOre than halfof the companies（53．7％），
andwecansee thatithasbeenwidelyspreadingin the automobile com−
paniesinJapanwhichusesocalled‘Kanban，’Wecanalsounderstandthat
it has been used and widely spreading not onlyinthe finalassembly
COmpaniesbutalsoinpar■tSaSSemblycompanies，andtheycansupplyparts andpr・OductsattheJust−inーTimemethodSmal1Llotprodalsoshares31 5％inJIThIfwe add both（miⅩed prod＋small−lot prod）together，SO
JITProductionandItsInfluenceonCostManagementinJapan −115−
spread in JIT
In MRP，Small−lot prod shares24A％ anditis ranked fir’StBut mediumJotprodis22．7％，mixedprodis204％，andsingle−lotprodis14 5％，andeachratioreachestoafairlygooddegreeInshort，inMRPitis Centeredon‘small−lotprod’andmedium−lotprod，butthereishigh−Variety ofloトSize Tosumuptheabovementioned，‘small−lotprod’，Whichincludessingle −lot，mixedprodandsmalトlot，amOuntStO749％inJOS，87。0％inJITand 59．3％inMRP，anditbecomesclearthat‘small−lotprod’ismostprevailing inJITJITissaidtobethemostadaptableto‘smallLlotprod’inJapan
Lastlylet us consider the pr・Oduction systems from the marketing featureofthecompaniesinTable−6Itistruebythetime−Seriesanalysis
thatwiththeincreaseofvarietyanddistinctivenessofconsumerneeds，the
ratio of production to order（PTO）hasincreased，and on the contrary PrOduction to stock（PTS）has decreasedAccording to Table−6，the PreSentStatuSisasfollows；PTOandPTSshare480％and495％respec− tivelyandtheyarebalancinginthetotalcompanies．PMS−wise analysis SaySthatPTOshar・eSmOrethan60％inJOSandJIT，andtheycenteredon PTOsystem．Ontheother hand，PTSsharesnear・1y67％anditcentered on PTSin MRP Table−6 Thevarietyofmarketing
Mar keting PTO PTS Both
Tota1 480 495 25
＊）PTOistheabbreviationforproductiontoorder，andPTSisproductionto stock
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4．Productslife−CyCleandcost reductionproblems
In this section，We reView company−wise pr・Oduct sales amounts by productslife−CyCle and check the product structure bylife−CyCleinthe COmpanyfirst”Nextwewanttoinqulreintotheinfluenceofthechanging Ofthepr’Oductlife−CyCleoncostmanagementWhenwereviewitfromthe Viewpointofthemanageabilityoftheproductcost Theratioofsalesamountsbyproductslife−CyCleisin TableM7。Sales amountsratioof‘1essthan3years’productsshares213％bysimplemean， andthatof‘3−6years’productsis21．6％r・eSpeCtively．Theratioofmore than‘6years’productsis57．．2％by simple meanWhenit comes to the Weightedmean，‘1essthan3years’and‘3，6years’arealittleover・25％each， and‘morethan6years’is477％anditislessthanhalfWecanunder’Stand thatthelarger the company scale becomes，the shorterthelife−CyCle of
productsit produces and the easierit can respond to the variety and individualityofconsumer needssmoothlyinJapan
Table−7 Salesratiobyproductlife−CyCle
Lessthan3years 3∼6years Morethan6years
Simple Weighted Simple Weighted Simple Weighted
JOS 214％ 331％ 197％ 200％ 589％ 469％
丁IT 251 256 331 38．0 418 36−4 MRP 20．0 199 206 330 594 471 TotaI 213 25。5 216 268 572 47。7 ＊）‘Eachyear’isdefinedasthetimeelapsedfromthebeginningofsellingnew products‘Weightedmean’isweightedbysalesamounts Respectivelytheshorterlife−CyCleproductssharethehighestratioin JITWhenwereviewtheweightedmean，WeCanfigureOut thatlarg−erJITProductionandItsInfluenceonCostManagementinJapan −117− JOScompanies，Whichareoccupiedmainlybylargerelectr・icalcompanles， haveasimi1ar trendandtheirproductlife−CyCleisbecomingshorterand ShorterWeseetheproductsof‘1essthan3years’shares33．．1％andthisis averyconspicuousresult．InJOSandMRP，theproductsof‘morethan6 years’sharemorethanthatofJITInshort，1argercompaniesareforced
andhaveabilityfor throwing newproductsintothemarketflexiblyand theycaneasilyadapttothechangingtaSteSOfconsumers7）
Thenreflectingontheabovementionedchangesoftheproductlife−
CyCle，howtheemphasisofmanagingcostisshi壬ting？Inordertoclarify thisproblem，Wedividedproductlife−CyCleintofivestages：PrOductpr・0一
子ect（PP），basic designing（BD），detailed designing（DD），preparation for production（PRP）andproduction（PR），Theresultsar・einTable−8（pres−
ent）andinTabler9（future）respectively“8），9）
According to Table−8，amOng the five stages，the prIeSent COntrOl− 1abilityofcostinPPisthehighest（23．8％）inthewholecompanies．The 7）InJapanautomobilecompaniesusuallymakemajorchangesofcar−mOdelsevery fouryearsandtheymakeminorchangeseveryyear Incaseofhome−electronics appliancecompanies，theymakemodel−Changeseverysix monthsThismight beaveryshortlife−CyCleofproducts，yOuCanunderstand TLheyalsohaveahigh −Variety ofproductline−up，aCCOrdinglytheyhavebeenchangingproductmodels alltheyearround
8）Aboutlife←CyCle costing，See B SBlanchard，Desなn and Manαge tO L娩Gycle
Cost，M／A Press，1978，and Tokyo University of Science（Cost Engineering
Group），Cos′rお曙eた1／宅，Cosf Pγ毎βCf∠7曙αf fゐe S毎㌍扉∧匂郷戸γPゐ（≠sβeぴgJ坤−
meni，（inJapanese），JapanValueI三ngineeringSociety，1985 9）Accordingto the definition of Tokyo University of Science［1985］，PPisthe
Stagefromgraspingtheconsumer needstodrawingtheproductplan，BDisthe
Stagemakingtheconcretebasicproductplanbasedontheproductproラectunder
the condition ofthe given function，SChedule and costDDis the stage for producingthe pr−Oductionspecificationslike manufacturing chartSbased onthe basicdesignundertheconditionofthegivenfunction，SCheduleandcost PRPis
thestagefinishingthepreparationformanufacturing（suchasprocessdesigning， makeorbuyout，prOducingthepattern，jigsandtooIs，andpurchasingmater・ials）
香川大学経済学部 研究年報 30 −，JJバー J′99∂ Table−8 Possibilityofcontro11ingmanufacturing・COSt（present） PP BD DD PRP PR JOS 200％ 223％ 194％ 165％ 219％ JIT 335 16．7 146 158 19．4 MRP 25．6 22−9 18′．7 15り4 17．5 0therS 24“6 181 133 146 29“4 Tota1 238 216 183 15“9 20 5 SeCOndis BD（216％），DDisthethird（183％），andPRPisthefourth（159 ％）Asthe order declines，themanageabilityofcost becomessmallerin the whole companies“If we compare the manag’eability of cost before
PrOductionstage（PP＋BD＋DD＋PRP）withthato壬PR′it（theratioof befor・eprOd）isnotsohigh（95％）asBlanchardpointedoutinhisbook，but itbecomesnearly80％．Thismeansabout80％ofproductcosthasalready beendecidedandmanagedattheplanningstage．．Accordinglythecontrol・ 1abilityattheproductionor manufacturingprOCeSSbecomeslessthan205 ％nowThistr・endwi1‖⊃eemPhasizedstillmorefromnowon
In details，PPis considered as veryimportantinJIT，and MRP attachesimportanceonPPandBDstages“Contrastedwiththoseresults，
JOSlaysmuchmorestressonthecontrolormanufacturingStage
Next let us review the future trend in Table-9 In all the stages of
PrOductplarming，eSPeCiaユ1yPPandBDareconsideredasmostimportant
forcostmanagementTheyaimatsqueezingandcontrollingthecostat thestageOfformingprOductconceptsanditispossibleandsignificantfor companies andit has been stillbecoming more and more crucialfor managingtheproductcost
In details，eVery PMS regarIds PPand BD as critical，but especially
JITattachesmuchimportancetocostmanagementattheplanningStageS
JIT ProductionandItsInfluenceonCost ManagementinJapan −119∼ Table−9ImportarLCeOfmanufacturingStageSOfproductcosts（future） PP BD DD PRP PR 2 0 2 0 0 00 0 7 2 1 2 1 9 3 5 0 3 4 4 2 2 2 2 2 3 4 ﹁⊥ 5 0 1 9 5 3 3 2 2 9 0 9 5 7 0 5 2 3 4 3 3 4 0 6 5 5 0 8 9 3 4 3 3 JOS JIT MRP OtberS Tota1 373 372 298 241 198
＊）The totalscore was reached by giving5points to the mostimportant element，，1tothe5thWeaggregatedthetotalscoreanddivideditbythe number ofrespondingcompanies
5．Costmanag・ementprOblemsandtheirtechniques
This section reviews what kind of problems areimportantin cost
managementandexaminesthetechnlqueswhichareusedfor’COStmanage・
mentintheJapanesecompanies
51Majorproblemsincostmanagement
The main problemsin cost management and theirimportance are
rankedin Table−10．In the whole companies，purChase management Of raw−materialsisthemostessentialtask（225），andthepointofitismore
thanO5pointaheadofthe2nd Thesametrendcanbeseenineverytype
OfPMSBeingrelatedto thattask，there arejobs of rationalization of
designing（112，5th）andmanagementOfsupplier・S（0．68，10th）Wecanalso understand theimportance of product planning；Pr’oduct planningin a narTOWSenSe，designlngandpreparationforpr・Oduction
The secondimpor■tant jobis quality controlincludingCOmpany−Wide qualitycontrol（TQC）．TQCiscloselyrelatedtothefieldworkofquality COntrOIcirclesThroughTQCandqualitycontroIcir・Cles，thecompanies
香川大学経済学部 研究年報 30 J．99（フ
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areimprovingthequalityofpTOductsandthemoraleoftheworkers．This CanbeseenineverytypeofPMSandeveryPMSregardsitverysignificant ThisisuniversallyessentialfortheJapanesecompanies anditisthepre− requisite for cost managementTQCis also gettingmuCh attention to
improvetheproductquality，SOCalledqualitycost，eSpeCiallyintheUS
A
Thethir・distheimprovement oftheyieldratio（146，3rd）whichaims atdecreasingthewasteofraw−materials．Thefourthisthereplacement
Table−10Importantproblemsofcost rLlanagement Maior problems JOS JIT MRP Total
1 2 3 4 5 6 7 00 9 0 0 2 3 4 5 6 1 1 1 1 1 1 1 5 3 6 7 2 1 4 1 9 8 8 7 5 8 7 9 2 7 4 2 1 1 0 0 6 6 6 6 4 3 3 0 2 1 1 1 1 1 1 1 1 3 5 4 6 5 8 7 1 0 2 9 3 3 5 6 1 1 1 1 1 1 1 1 9 1 5 2 7 7 7 2 3 5 8 6 6 4 4 2 5 00 3 ハU 2 8 9 7 7 4 8 3 3 3 1 2 1 1・⊥ 1 1・⊥ 1 1 2 7 8 3 8 4 5 4 6 0 2 1 5 3 6 1 1 1 1 1 1 1 2 0 2 6 2 6 6 2 6 6 0 8 2 6 0 0 ︵＝六︶ 9 9 8 3 8 2 1 3 0 8 4 7 1 4 0 l l l 1 2 1⊥ 1 2 つJ 4 6 7 5 8 0 1 9 1 3 4 5 6 1 1 1 1 1 1 1 6 6 5 9 5 8 6 5 3 7 6 7 9 2 8 8 1 7 3 2 1⊥ O 1 9 7 5 8 5 4 4 3 0 2 1 1 1 1 1 1 PuTChasernanagementoiTaW−materials Company−Widequalitycontrol（TQC） lmpIOVementOfYieldratio Replacementofmachineryorequipment Rationalizationoidesignlng Maintenanceofhigheroperationratio ShortageOflabourtime Reductionoffactoryexpenses Inventory control Rationalizationofproductionprocess Managementofsuppliers Changeofraw−materials Standardizationofjob Standardizationofproducts R＆Dmanagement OtherS ＊）FiguresaretheweightofimportanCe，andnumbersintheparenthesesaretheorder OfimportanCeincostmanagementThetotalscorewasreachedbygivlng5pointsto themostimportantelement，4tothe2nd，，1tothe5thWeaggregatedthetotal SCOreanddivideditbythenumbersofrespondingcompanies
JIT ProductionandItsInfluenceonCostManagementinJapan −121−
Of machinery or’equipment（1．．27，4th）reflecting on the recent factory automation（FA）orf1exiblemanufacturingsystems（FMS）Otherimpor− tantissuesaremaintenance of higheroperationratio（111，7th），Shortage Oflabourtime（1，04，7th）andreductionoffactoryexpenses（1。01，8th） Liningupmajor costmanagementproblemsbyPMS，JOShassimilar Orderswiththegeneraltrend，butshortageoflabourtime，managementOf Suppliers andinventorymanagementar’eStillmorecrucialissues，because JOSisconstitutedmainlyofassemblyprodandmechanicalprocessprod InJIT，purChasemanagement Ofraw−materialsranksbyfarthefirst （2”82）andrationalizationofdesigningisalsor・anked3rd（1．．32）Thecritical
issues of product planninghaveincreased their significance above all
Rationalization or’COntrOlof production processes such as shortage Of labour t．ime（1…26，4th），rationalization of production process（1…06，6th） rankednexttothem，Inadditiontothem，reductionoffactoryexpenses （112，5th）whichmeansthereductionoftheoverheadcostofthefactor’yaS awhole，isalsocrucialproblemり Ofcour−SequalitycontrolincludingTQC
isranked the2nd andisconsidered as very essentialandthisisthesame
trendwithother・PMSsandthescoresar・eStillhigherthanother’CaSeSOn theother・handimpr・OVementOfyieldratio，replacement ofmachineryand equipment，andinventorycontr’01decreasetheirscores
In MRP，purChase management Of■raw−materialsis also ranked the
first，but other crucialissues areimpr・0Vement Oiyield ratio（181，2nd）， r・ePlacement ofmachiner・y and equipment（135，4th），andmaintenance of higheroperationratio（127，5th）．Thisisalsocloselyr’elatedtothetrend
ofMRPinwhichtheratiosofchemicalprocessprodaremuchhigherthan
Other PMSs
Judgingfr・Omtheaboveresultsby PMS，We Canunderstandthatthe
香川大学経済学部 研究年報 30 ノー990
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thetechnologicalcharacteristicsofthecompanies10）
5。2 Costmanagementtechniques
In this paragraph，We reView what kind of techniques are usedin
SOlvingCOStmanagementprOblemsbyTable−11・Thecommonfeatur’eSin
allPMSs are asfo1lowsBudgetary planning andcontrolisparticularly
Table−11CostmanagementteChniques
Techniques JOS JIT MRP Total
769（1） 735（1） 425（3） 5。05（2） 463（2）461（3） 3、53（7） 379（4） 401（4） 367（5） 374（5） 355（6） 345（8） 347（7） 3、56（6） 324（8） 240（9） 208（9） 74（10） 39（10） 10（14）15（11） 11（11）14（12） 11（11）12（13） 11（11） 10（14） 1 2 4 5 7 8 3 6 9 3 4 0 2 1 1 1 1 1 1 9 ハリ 5 3 7 6 3 2 5 0 0 0 8 ハリ 6 2 4 0 0 6 1 1 6 1 0 2 1 2 7 6 4 4 3 2 5 3 2 1 2 3 4 6 5 7 8 9 1 0 2 3 4 1 1 1 1 1 0 3 7 4 8 9 0 0 4 ∩り︶ 3 6 8 3 9 6 6 7 5 6 1 2 6 1 2 1 0 0 6 5 4 3 3 3 3 3 1 BudgetaryplanningandcontroI Costproiect／COStengineering CompanY−widequalitycontTOl（TQC） Actualcostaccounting Quantativestandardsinprod mgmt Stanardcostaccounting VE／VA Managementbyobjectives（MBO） Industrialengineering（IE） Simulation PERT／CPM Regression analysis Mathematical programming Others ＊）Figuresaretheweightofimportance，andfiguresintheparenthesesaretheranks ofimportanceincostmanagementThetotalscoreWaSreaChedbygiving14points tothemostimportantelement，13tothe2nd，川，1tothe14thWeaggregatedtotal SCOreanddivideditbythenumberofrespondingcompaniesandmultiplylO／14 10）SeeInoue，S，“RecentDevelopmentsofCostManagementProblemsunderTech． nologicalChangesinJapan，”ResearchPaperNo30（DepartmentOfInformation Science，Kagawa University），May1988，pp18−21
JITProductionandItsInf1uenceonCostManagementinIapan −123−
important．inJapan，and cost project／cost engineeringll）and TQC are
essentialtechniques for cost management ofJapanese companies．The
abovementionedarethethreekeyandrequiredtechniquesforcostmanage・
mentinJapan
Precisely，inJOSbudgetar’yplanningandcontrolisfirstranked（6，，90）， costproject／costengineering（genkakikakuinJapanese）issecondranked （563）and TQCis third ranked（467）The traditionalcost management techniques based on accounting such as actualcosting（3．74），Standar−d COSting（3．．69）areranked4thand5threspectivelyinJOSThesemethods
arestillconsideredascomparativelymoreusefulforcostmanagementin JOS thanin other PMSsh Quantitative standards based on production
management（6th），VE／VA（8th）andIE（9th）followthoseitems”Manage− mentbyobjectives（MBO），basedonactiveandvoluntaryparticipationof fieldworker・S，holdsthe7thpositioninJOS InJIT，budgetaryplanning andcontrolranksthelstanditsfigur・eis thehighest（7，69）amongthreePMSs．ThecharacteristicaspectsinJITis thatcostproject／costengineer・ingishigherimportanceattached（6．20，2nd） andatthesametimeVE／VAwhichisusedforcuttingdownthe drifting COSt（nariyukigenkainJapanese）andapproachingtOthetarg■etCOSt（moku− hyogenkainJapanese）occupies the3rd（5．13）．TQCisranked4th（4A5）
and MBO maintains the sixth place By combining those techniques
togetherandutilizingtheenergyandcor・pOrationoffieldworkerIS，JITis
abletoreduceproductcostsandbecomestillmorecompetitivethanother
PMSs．Standardcostingandquantativestandardsinproductionmanage− mentbecomereverselyユessimportant
11）This js also calied‘target costing’，，Precise explanation on target costing，See Sakurai，M，‘TargetCostingandHowToUseIt，’ルurnalQf CosiManagemenち Vol3No2（Summer・1989）
ーJ2∠≠− 香川大学経済学部 研究年報 30 J．990
FinallyinMRP，budgetaryplanningandcontrolisalsothemostimpor・ tant（7．69，1st），the secondis TQC（463），the thirdis cost project／cost
engineering，thefourthisquantativestandardsbyproductionmanagement
（401）and standard costing ranks fifth（374）TQC and MBO which are
basedonthefieldmanagementarealsousefultechniquesinMRP 6．ChangingCOStStruCtureandinventoryassets
This section reviews recenttrendofcoststructure andstock ofinven−
toryassetssuchasstocksofraw−materials，WOrk−in−prOCeSSandproducts reflectingOnthesystematizationofcostmanagement，Changesofpr・Oduc・ tionsystemsbasedonthevarietyandpersonalityofconsumerneeds，Atthe Sametime，reViewingthechangeOfsignificanceofeachcostelementinthe pastandinthefuture，WeCangueSSthefutureimportantelementsoncost management 61Thestructureofproductcosts Herewereviewtheratio ofeachcostelementsuchasdirectmaterial
COSt，indirect materialcost，directlabour cost，indir’eCtlabour cost，pay− ment to subcontr’aCtOrS（suppliers），deprIeCiation expenses，0Ver・head cost
and fixed cost
6。1．1The ratio of materialcost
（1）Dir・eCtmaterialcost
Directmaterialcost（DMC）isalittlemor・ethan60％bysimplemean
and67％byweightedmeaninJITand MRP respectivelyThese figures
areconsider．ablyhigherthanthoseofJOS（54．1％bysimplemean，53‖6％by Weightedmean）Atthesametimether・atioofDMCbecomesmuchhigher inlar’gerSCalecompanies”Ontheotherhand，inJOSitsfigureisaround
JITProductionandItsInfluenceonCostManagementinJapan −125− Table−12 Theratioofdirectmaterialcost（DMC） γ⊥ e u t u F Simple Weighted 8 1 2 5 6 6 1 0 2 5 6 6 9 9 9 6 2 6 1 5 3 1 TOS 541％ 536％ JIT 614 673 MRP 600 676 一Tota1 572 615 9−56 68 60 ＊）Weightisweightedbyproductcostamounts‘Order’（thescoreorpointof importanceforcostmanagement）wasreachedbygiving8pointstothemost importantelement，7tothe2nd，，1tothe8th− Weaggregatedtotalscore
and dividedit by the number of respondingCOmpanies and multiplylO／8
Theriseandfallratio（RFR）wascalculatedbythefollowingformula（The number ofcompanies which answered‘increased’）／（The number ofcom・ panies which answered‘decreased’）The followingCOSt ratio tables are calculated asthesame asthisnote
54％regardlessofcompany−SCales12）
DMCisthemostimportantcostelementforcostmanagementinever・y PMS judging fr・Omits bigger・ratio“The rise and fal1ratio（RFR）has
increasedalittleinJITinthepast，but2／30fthecompaniesexpectRFR 12）Notethat20companiesofJITincludepaymenttosubcontractor・S（PTS）inDMC Thisistheresultthatbuyingmaterialsandsubcontractingpartsorcomponents arebecomingthesimiJarkindsofactivitiesespeciallyinJIT According■1ythere isnonecessityfordistinguishDMCfromPTSIfweadd（DMC＋PTS）together， WeCanObtainthefollowingfigur−eS Sjmple Weighted JOS 652％ JIT 68 4 MRP 65‘7 Tota1 6587 687
香川大学経済学部 研究年報 30
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to decreasein the futureThisis one of the causes and motives that
purchasemanagementOfraw−materialsisveryimportanttargetforcost reductionespeciallyinJITandMRP
（2）Indirectmaterialcost（IMC）
Indirectmaterialcost（IMC）isalittlemorethan3％bysimplemean， anditdecreasesto24％byweightedmeaninTable−13．InJOSandMRP
thelarger the company scale becomes，the smaller the ratio ofIMC
becomes．On the contraryinJITitis nearly the sameindiffer・ent tO company−SCaleMorecompaniesinJOSandMRP（especiallyJOS）under− standIMCdecreasedinthepastandisdecr・eaSinginthefuturetooButin JIT，IMCincr・eaSedinthepastandwillincreaseinthefuturetoo Table−13 Theratioofindirectmaterialcost（IMC） Simple Weighted u F ・↑し r u e T OS 32％ 27％ JIT 33 31 MRP 34 2．1 2 8 6 8 3 3 3 4 3 9 3 6 5 3 7 1 3 0 2 6 5 9 1 Tota1 3．2 24 372 73 78 （3）Directlabour cost（DLC） Dir−eCtlabour・COSt（DLC）isinTable−14Wecanunder・Standfromtwo meansthatther’atioofDLCisalittlesmallerin1argercompanies。Wesee thesametrendinJOSandMRP，butitisrever・SedinJITTheorder（the SCOr’eOfimportanceforcostmanagement）isthe2ndandstillsignificantas itwas，becausetheratiostillholdsthe2ndnexttoDMCinJapan．Ther・ise andfallratio（RFR）ofDLCinthepastisalittledecreasedinJIT，butin OtherPMSs，itisintheoppositedirectionButthefutur・eRFRofDLCis expectedtodecreasealittleineveryPMS
汀T Production andItsInfluenceonCost ManagementinJapan ∼127−
Table・14 Theratio ofdirectlabour・COSt（DLC）
Simple Weighted 6 0 3 2 8 0 1 1 122％ 118％ 110 1155 119 93 Total ll9 10−5 793 110 67 （4）Indirectlabour・COSt（ILC）
The ratio ofindirectlabour cost（ILC）isin Table−15。In t，he total COmpanies，theratioofILCissmaller（51％−33％＝18％）in1argercom− panies．RFRincrIeaSedinthepastin most companies，but the r・atiowi11
Slightlydecreaseinthefuture Table−15 Theratioofindirectlabourcost（ILC） Future Simple Weighted 8 9 3 り︼ −1 、い 2 1 1 57％ 37％ 5，4 32 43 31 Tota1 5。1 33 431 192 84 （5）Paymenttosubcontractors（PTS） Theratioofpaymenttosubcontractors（PTS）isinTable−16”PTSis thehighestinJOS，anditdecreasesinaccordancewithJITandMRPboth insimplemeanandweightedmeanThisseemstohaveacloserelation−
Shipwith the number of assembly prod companies whichar・eincludedin each PMS（see Table−2）Thisis also r・eflected on‘order・’13）RFR has
香川大学経済学部 研究年報 30
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increasedinthepastina11PMSs，butinthefutureitwi11be‘increased’a littleinJOS，butJITexpectsit‘decreased’inabout3／40fthecompanies，
tooThinking from the recent trend，PTS as wellas materialcost has beensurelyaddingvalueincostmanagementinJapan Table−16 Theratioofpaymenttosubcontractors（PTS） Order Simpie Weighted 、 TH▲ u t r e JOS l12％ 96％ 622 2022 JIT 70 50 492 1466 MRP 57 41 4．49 2．29 9 7 8 1 3 5 1 1 Tota1 86 72 543 195 121
＊）Payment to subcontractorsisincludedin directmaterialcost of20com・ PaniesinJITproduction （6）Depreciationexpense（DPE） RecentlyinvestmentonproductiontechnologysuchasFA or FMSis becomingdistinctiveinordertoproduceproductsofshor．tlife−CyCle，high ーVarietyandlow▼VOlumeInaccordancetothatphenomenon，themanage− Table・17 Thetrendofdepreciationexpense Simple Weighted u t e r 3 6 5 6 9 6 ノーイ1 ■4 4 5 4 2 0 7 4 7 0 ウん 2 2 2 8 7 7 9 1 8 4 6 8 0 ﹁⊥ 3 5 5 Tota1 456 4．55 452 3355 ＊）Weightisweightedbyproductcostamounts
JIT Production andItsInfluence onCost ManagementinJapan −129−
ment of DPE has especiallyincreased theimportanceinmanagement ThatcanbejudgedfromthefactthatDPEhasincreaseditssharefrom3 47％（1981）to4“56％（1986）bysimplemeanforthesefiveyears JITandMRPsharehigherratioinsimplemean，butitsratioisnot
muchdifferedamongthreebyweightedmean RFRhasincr・eaSedinthe
pastinmostcompanies，eSpeCia11yinJITInthefuturethecompanies whichthinkRFRofDPE‘incr・eaSe，aretwiceasmuchof‘decrease’，there一 重or・ethemanagementofDPEisverycriticalinhigh−teChnologyera （7）Indirectcost（IDC） Therelationshipbetweentheratioofdirectcostandindirectcost（IDC） affects the manag−ement Of the product manufacturing costTabler18shows the ratio ofIDC“HereIDC ＝［product manufacturing cost
−（DMC＋DLC）］TheresultshowsusthatIDCissmallerinlarger COm− paniesthaninsmallercompaniesbycomparingsimplemeanwithweighted
meaninthetotalcompanies．PMS−Wiseanalysisshowsthattheratio of
IDC becomeslessinJIT thaninother PMSs．Thistrendisremarkable
inlarger COmpaniesJOS has the reverseresult toJIT・These results
haveinfluencedcostreductionandthisisref1ectedoncostmanagementin JIT，Whichstressestheimportanceofcostreductionofraw−materialsand therationalizationofdesigning Table−18 Thetrendofindirectcost（IDC） Simple Weighted JOS 33“7％ 346％ JIT 276 21“3 MRP 28，1 23．1 Tota1 310 28．1
香川大学経済学部 研究年報 30 J99（フ
−J、い
（8）Fixedcost（FDC）
Depreciationexpense（DPE）hasbeenincr−eaSingitsratioastheresult
ofintroducingFAorFMSReflectingOntheincreaseofDPE，fixedcost
（FDC）has beenincreasingits ratio shownin Table−19That trendis
reflected on RFR of the past．In the whole RFRincreasedits ratioin Smallercompaniesinthepast IndetailsJITandJOShave asimilar・trendwiththecompaniesasa whole，andsmallerJIThaveespeciallyincreasedtheratioofFDC“Onthe otherhand，inMRP，1argercompanieshaveincreaseditsr−atioIWecan notdecidethetr・endof FDConersidedly Table−19 Thetrendoffixedcost（FDC） FDC RFR
Simple Weighted Past r e
u t u F 8 3 4 9 6 0 0 0 1 JOS 261％ 206％ 158 JIT 282％ 179 169 MRP 230 268 179 Tota1 254 214 165 096 61．2 0ther costsofsales（COS） Whenwemanagethetotalcostofthecompany，Weneedtowidenour attentionnot onlyto theproductmanufacturingcostbutalsotocost of sales such as sales expenses，generaland administrative expenses and
financialexpenses（interestpaid anddiscountcharge）．Thereductionof thoseexpensesisalsover・yCriticalelementfortotoalcost management， acording・lycostsofsales（COS）ar’ereviewedinthispart （1）Salesexpenses（SAE） Theratioofsalesexpenses（SAE）isshowninTable−20According−tO theTable，theratioofSAEis862％bysimplemeanand7h77％byweighted
TIT ProductionandItsInfluenceonCostManagementinJapan −131−
meaninthewholecompaniesItcanbesaidthatthesmallerthecompany
is，the higher the ratio of SAE becomesIn details the ratio of SAE
becomessmallerinJOSandJITThisshowsthecloserelationshiptothe
Shar’eOfproductionto order（PTO）… PTOsharesmorethan60％inJOS
andJITanditisespeciallytrueinJITOntheotherhand，inMRPwhich
Shares more than66％of production to stock（PTS），the ratio of SAE
becomesmorethanlO％Thisalsoexplainsthat PTSneedsmuchmore SAEfor advertisingandsellingtheirproducts
Table−20 Theratioofsalesexpenses（SAE）
SAE RFR
Simple Weighted Past Future
IOS 780％ 639％ 256 209 丁IT 568 5．58 230 158 MRP lO51 1018 289 3088 Tota1 862 777 264 229 ＊）SAEratio＝Salesexpenses／salesamount xlOOWeightisweightedby SalesamountsThisisthesamefromTable−20to Table−22 RFRofSAEincreasedinmostcompaniesinthepastanditwi11be
guessed toincreasein the future toohIt explains that the marketing activitiesincreasetheimportancemoreandmorefromnowoninallPMSs， anditwi11bereflectedontheimportanceofmanagementOfSAE
（2）Administr・ativeandgeneralexpenses（AGE）
Nextletusreviewadministrativeandgener・alexpenses（AGE）inTable−
21TheratioofAGEis715％bysimplemeanand6A7％byweighted
mean respectively，therefore the ratio of smaller companiesis alittlehigher thanthatoflargercompaniesThepointofRFRwas2．82inthe pastandSAEincreasedinthepastinalmostallthecompaniesbutRFRof
香川大学経済学部 研究年報 30
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thefutureisO．87point，aCCOrdinglyitcanbeguessedandexpectedRFRto
decrease from now on
SpecificallyitisthecharacteristicthatAGEinJITis468％bysimple
meanand408％byweightedmean，andtheseareespeciallysmallerfigures
COmparedwiththose of other PMSs，Theratio of RFRwhich answered
‘increased’isconsiderablyhighinthepastinallPMSs，andthisisespecially
trueinJIT
Table−21Theratioofadministrativeandgeneralexpenses（AGE）
AGE RFR
Simple Weighted Future
T OS 714％ 736％ JIT 468 4088 MRP 822 6−99 3 5 1 5 7 1 2 3 3 Tota1 715 647 282 87 ＊）AGEratio＝AGEamount／Salesamount xlOO （3）Financialexpenses（FE）
The ratio offinancialexpenses（FE）is another veryimpor’tant COSt element for company−Wide cost managementIn Table−22，the ratiois
Table−22 Theratiooffinancialexpenses（FE）
FE RFR
Simple Weighted Past u F t u r e
TOS 240％ 281％ 31
丁IT 138 120 48
MRP 2′32 204 39
﹁⊥ 2 0 3 4 2
Tota1 225 231 36 27
＊）Financialratio ＝（interest paid 十 amount of discount charge）／saies amount xlOO
JIT ProductionandItsInfluenceonCostManagementinJapan −133山 around2．3％（bothsimplemeanandweightedmean）intlletOtalcompanies， RFRofFEisdriftingto‘decrease’inmostofthecompanies Indetailstheratioof FEinJITisabouthalfofotherPMSs，andJIT areespeciallyenthusiasticforcompany−Widecostmanagement Ofcourse RFRofFEisconsideredsharply‘decrease’notonlyinthepastbutalsoin thefutur・einalmosta11thecompaniesinJapan 6“2 Theshiftofturnover・periodofinventoryassets（TIA） Recentlyitisoftenpointedoutthatminimizingtheinventoryassetsis cruciallyessentialfordecreasingthepr・OductmanufacturingCOStThisis particularlyemphasizedandtrueinJITcompanies，Inthisparagraph，We examinethechangingtumoverperiodofinventoryassets（TIA）suchasraw rmater・ials，WOrk−in−prOCeSS and finished goods（products），and RFR of stocks by PMS”Of cour・Se，itis true that thereis a certain requir−ed
Optimizedlevelof stocks depending on theindustriesAccordingly，We
cannotsimply compareit with others，butwe wouldlike to pr’eSume an
approximatetrendofTIAbyPMS
（1）Thetrendofstock ofinventoryatpr’eSent
Thepresent TIAisinTable−23Thetumover period ofrawrmate− rials（TRA）inthetotalcompaniesisOり33monthbothbysimplemeanand
Table−23 Turnoverperiodofinventoryassets（TIA）atpresent Raw−materials Work−in−prOCeSS Products Total Simple Weighted Simple Weighted Simple Weighted Simple Weighted JOS 35 38 106 130 75 62 217 231
JIT 15 08 33 27 45 40 93 76 MRP 35 30 39 39 117 79 191 148
Tota1 33 33 71 76 88 67 192 17777
＊）TurnOVer period ＝inventory’aSSetS／Sales amounts x12‘Simple’is Simplemeanand‘weighted’meansⅥeightedmean
ーJ34一 香川大学経済学部 研究年報 30 J990
Weighted mean respectivelyThat of wor・k−in−prOCeSS（TWP）is O71
monthbysimplemean，andO．76byweightedmean．TheturnOVerperiod Ofproducts（TPP）isO…88monthbysimplemeanandO．67monthbyweighted mean”Judgingfromtheresults，TPPisshorterin1argercompaniesbythe CaSeOfthetotaicompanies WhenweexamineTIAbyPMS，WeCanfindthatanyTIAsuchasr・aw −materials，WOrkrin∼prOCeSSOrprOductsinJITisparticularlyshorterthan thoseofotherPMSseitherbysimplemeanorweightedmeanAccording−
1y TIAinJITis much shorter as well“The trend of shorter TIAis
COnSpicuousespeciallyinlargerJITcompanies TIAofMRPisthesecondaryshortest，anditmaybederivedfr・Omthe CharacteristicofMRPitself，aSTPPofMRPisthelongest amongthr−ee Thismaycloselyrelatedwiththefeatureo士MRPwhichsharesthehighest ratio ofPTScompanies InJOStheturnoverperiodiscomparativelylongerthanotherPMSsin ever・yStage（raw−materials，WOrk−in−prOCeSSandproducts），andthetrend isespeciallyclearanditisthelongestinwork−in−prOCeSSThistr’endis StreSSedinlargerscalecompaniesThisiscloselyrelatedtothefactthat
JOSincludes higher ratio ofassemblyprod and mechanicalpr・OCeSS PrOd （especiallytheratioofmechanicalpr・OCeSSpr・Odishigher’）
（2）Thetrendofstockofinventoryassetsinthefuture
Lastlylet us examine the future trend ofstock ofinventory assets
（RFR）in TableM24．In every PMS，almost a11the companies take for gT・anted that the stock of raW−materials，WOrk−in−prOCeSS and finished goods（products）willbepositivelydecreasingfromnowon”InJapanese
manufacturingcompaniestheystrivetoreducethestockofinventoryand theyhaveachievedittoagreatextentinthepast Atthesametimethey
JIT PrOduction andItsIn士1uenceonCost Managementin Tapan −135一
Table−24 Thefutur・eOfstockofiIlVeIltOryaSSetS
Items Raw−materials Work−in−prOCeSS Products
5 2 4
1 1 1
11 14
＊）ThefigureiscalculatedasthesamewayasRFRinTable▼12 7．Conclusion
Inthispaper，WereViewedinformationsystem for cost management， Var・ietyanddistinctivenessofconsumerneedsanditsinfluenceonproduc− tion systems，ShorteningOf productlife山CyCle anditsinf1uence on cost reductionproblems，majorcostmanagementproblemsandtheirtechniques，
and cost structure and changes of turnover period ofinventory aSSetSin Japanesecompanies
First，COmputerSyStemShavebeenalreadyactivelyintroducedinevery PMS，eSpeCiallyinJIT for systematization of cost management andit
reaches to a considerablelevel Database systems（DBSs），Which ar・e
VeryuSefulformulti−purpOSeSOfcompanyinformation，areCOnSideredto
havebeenintroducedto some extent and theywi11continue tointroduce DBSincreasingly Second，eaChmanufacturingCOmpanyinJapanhasadvanceditshighr Var・ietyandsmalllot−Sizepr・Odintensivelyinorder’tor’eSpOndtothehigh− varietyandindividualityofmarketingandconsumerneedsThetr’endis mostclearinJIT，anditcanbeseeninotherPMSsaswell”Concerning theproductvolume，Ofcourselow−VOlumepr．oductionisthemainsystem， but medium−VOlume production and high−VOlume production also share
香川大学経済学部 研究年報 30
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Accordingly，We CannOt define thatlow−VOlume productionis the only systemthatJapanesemanufacturingcompanieshaveintroduced1’1）Thereis a considerable variety of product←VOlume whichis pr’OducedinJapanese COmpanies
TheshorteningOfproductlife−CyClehasalsoadvancedineveryPMS， especiallyinJIT Atthe sametimelarger scale companiesinelectr■ical machineindustr・yinJOS also have the simi1ar trendTheinfluence of
shorteningofproductlifeCyCleforcostmanagementcanbeseeninthefact
that the stage ofplanning（cost planning）such as pTOduct planning and
designingis attached muchimportance for cost management．Judging
fromthistrend，eVeryCOmpanyWi11increasethestresson‘costplanning’
muchmoreandstrengthenthecost management atthelevelof planning
For that purpose，eVery COmpany needs to develop usefultechniques for
COSt management at the stage Of cost planning such as cost pr’Oiect／COSt
targeting
We could understand that the stage of cost planning，SO Called‘up−
Streammanagement’，SuCh asrationalizationofdesigning，PurChaseman− ag−ement Of r−aW−materials had been becomingimportant for cost management。15）Depending on the changes of cost management prOblems， newcostmanagementtechniques，SuChascostproject／costtargeting，are
prevailingwidelyinlayingstressonJIT
Whenweseecostmanagementfr■（）mthecoststructure，WeCanunder−
StandthatJIThasbeenreducingnOtOnly theproductmanufacturingCOSt butalsothecostofsalessuchasgeneralandadministrativeexpenses，Sales
14）SeeInoue，S，‘A Trend of H短hVariety，LowVOlume and SmallLot−Size Pr’0− ductioninJapanese Manufacturing Companies−−Comparisonwith That of Eur− Opean and American Companies−，’The Kagau）a Unlve71Si！y Economic Reuieu）， Vo161No3：December1988，pp124一一135（inJapanese）
15）Seelforexample，Hiromoto，T，‘AMemorandumon ManagementAccounting，’ HltOtSubashiReuieu），VollOO No5，November1988：（inJapanese）
JrT ProductionandItsInf1uenceonCostManagementinJapan −137−
expensesandfinancialexpenses，andwecouldseethatJIThadbeenaiming
atthecompany岬widecostr’eduction
I．，aStlyitis often pointed out thatJapanese companies have been actively struggling to r・educe the turnover period ofinventory assets Accordingto our surveyresearch，We COuld also r−eCOnfirm thatJIT had gr・eatlyreduceditsturnOVerperiodofinventoryassetssuchasstocksofraw rmater’ials，WOrk−in−prOCeSS and finished goods comparedwith those of
OtherPMSs”Japanesecompanies，nOtOnlyinJITbutalsoinotherPMSs， ShortenedtheturnoverperiodaggT’esSivelyinthepastItisalsoclear−that Japanesecompanieswillcontinueactivelytomakeeffortsforattainingthe ‘zero−inventory’too．ThisisthefinalgOalandinthetruesenseoftheword itistheJust−in−Time（JIT）productionanddeliverysystem ［APPENDIX］ WewouldliketobrieflyexplainaboutthesurVeyThesurveywasmadein
1986−87for 7 months．The questionnaire was mailed to 926 manufacturing companieslistedonTokyoStockExchangesand533companiesrespondedThe
responseratiowas576％ButthereareCOmPanieswhichmarkednothing（20），
and there are27companies marked nothing about PMSsThose companies mentioned above are excludedThenJOS companies are232，Jrr are54and MRP are174and others are26，but here we exclude the data of others for
comparingJITwithJOSandMRP Accor・dinglythetotalfigures（orscores）of
JOS，JITandMRPdonotnecessarilyaccordwithfiguresofthetotal TheoutlineoftherespondingcompaniesbyPMSsisasfollowsThemajor
introducingcompaniesofJOSチregeneralmachinery（50companies，216％），
electricalmachinery（47companleS，203％），and chemicals and steel（20com・ panies，86％respectively＝ITismainlyintroducedbytheindustriesoftrans・ POrtequi甲1ent（20companies，37｝0％），generalmachinery（13companies，201％）｝ andelectrlCalmachinery（9companies，167％）MRPismainlyintroducedbythe industries of chemicals（61，351％），foods（23，132％），electr・icalmachinery（23， 132％），andceramicsandstone（13，75） ThebriefinformationofrespondingcompaniesbyPMSisasfollows：
香川大学経済学部 研究年報 30
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GeneralinformationoftheresporLdingCOmpanies（1）
Capital Sales Mfgcost Employees Factory Decentralized JOS ll，577 159，445 114，028 3，906 JIT 6，887 165，759 136，170 4，319 MRP 13，344 185，372 112，973 3，678 1 7 5 5 1 0 4 4 5 T、otal ll，654 175，128 119，003 3，825 468 36 4 ＊）Capitalamounts，Sales amounts，prOduct manufacturing cost（￥mi11ion Yen），
the number of employees（person），the number of factories（unit），decentralized
division（ratio）
GeneralinformationoftherespondingCOmpanies（2）
Operation E，ⅩpOrt MajorpIOducts Investment R＆Dexpenses
IOS 879％ 160％ 883％ 607％ 262％ 甘T 996 136 935 700 2822 MRP 867 110 895 555 3 32 Tota1 883 140 892 598 2 85 ＊）Operationratio（％），eXpOrtratio（％），andmaiorproductratio Investmentratio （％）andR＆Dratio（％）ar−etheratiostothetotalsalesamounts
