物流管理文献翻译原文及译文Word文件下载.docx
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N.Prindezis,C.T.Kiranoudis
SchoolofChemicalEngineering,NationalTechnicalUniversity,15780Athens,Greece
Received13September2003;
receivedinrevisedform20December2003;
accepted27January2004
Availableonline10December2004
Abstract
ThispaperpresentsanInternet-BasedLogisticsManagementSystemtocoordinateanddisseminatetasksandrelatedinformationforsolvingtheheterogeneousvehicleroutingproblemusingappropriatemetaheuristictechniques,foruseinenterprisechainnetworks.ItsarchitectureinvolvesaJAVAWebappletequippedwithinteractivecommunicationcapabilitiesbetweenperipheralsoftwaretools.ThesystemwasdevelopedindistributedsoftwarefashiontechnologyforallcomputerplatformsutilizingaWebbrowser,focusingonthedetailedroadnetworkofAthensandtheneedsoftheAthensCentralFoodMarketenterprises.2004ElsevierLtd.Allrightsreserved.
Keywords:
Decisionsupportsystem;
e-Logistics;
Transportation;
Vehicleroutingproblem
1.Introduction
Enterprisechainsarethebusinessmodelofthepresentandfutureregardingmarketsthatinvolvesmallandmediumcompanysizes.Clearly,groupingactivitiestowardsafocusedtargetfacilitatesanunderstandablyimprovedmarketpenetrationguaranteedbyasuccessfultrademarkofaleadingcompanyinthefield.Severalcollaborationmodelsthatbasicallyincludefranchisingareintroducedasapartofthisintegratedprocess.Whensuchanetworkisintroducedinordertoexploitacommercialideaorbusinessinitiativeandsubsequentlyexpandedasmarketpenetrationgrows,severalmanagementissuesariseregardingtheoperationsoftheentirenetwork.SuchanetworkistheidealplacefororganizingandevaluatinginamorecentralizedwayseveralordinaryoperationsregardingsupplychainandlogisticsInfact,toolsdevelopedfororganizingmanagementprocessesandoperationalneedsofeachindividualcompany,canbedevelopedinamorecentralizedfashionandtheservicesprovidedbythetoolcanbeofferedtoeachnetworkmembertofacilitatetransactionsandtackleoperationssimilarly.Web-basedapplicationsareanidealstartingplacefordevelopingsuchapplications.Typicallysuchsystemsserveasacentraldepotfordistributingcommonservicesinthefieldoflogistics.Thecommercialapplicationisstoredinacentralserverandservicesareprovidedforeachmemberofthegroup.Aprototypeofsuchaserverisdescribedinapreviouswork(Prindezis,Kiranoudis,&
Marinos-Kouris,2003).ThispaperpresentsthecompletedinternetsystemthatisinstalledinthecentralwebserveroftheAthensCentralFoodMarketthatdealswiththeintegratedproblemofdistributionfor690companiesthatcompriseauniquelogisticsandretailchainofenterprises.Theneedsofeachcompanyareunderlinedandthealgorithmsdevelopedaredescribedwithintheunifiedinternetenvironment.Theproblemsolvedandservicesprovidedforeachcompanyistheoneinvolvingdistributionofgoodsthroughaheterogeneousfleetoftrucks.Newinsightsofthemetaheuristicsemployedareprovided.Acharacteristiccasestudyispresentedtoillustratetheeffectivenessoftheproposedapproachforareal-worldproblemofdistributionthroughthedetailedroadnetworkofAthens.
2.Distributionthroughheterogeneousvehiclefleets
Thefleetmanagementproblempresentedinthispaperrequirestheuseofaheterogeneousfleetofvehiclesthatdistributegoodsthroughanetworkofclients
(Tarantilis,Kiranoudis,&
Vassiliadis,2003,2004).Therefore,thesystemwasdesignedinordertoautomaticallygeneratevehicleroutes(whichvehiclesshouldde-
livertowhichcustomersandinwhichorder),usingrational,quantitative,spatialandnon-spatialinformationandminimizingsimultaneouslythevehiclecostandthetotaldistancetravelledbythevehicles,subjecttothefollowingconstraints:
●eachvehiclehasapredeterminedloadcapacity,typicallydifferentfromallothervehiclescomprisingthefleet(heterogeneousnature),
●thecapacityofavehiclecannotbeexceeded,
●asinglevehiclesupplieseachcustomersdemand,
●thenumberofvehiclesusedispredetermined.
TheproblemhasanobviouscommercialvalueandhasdrawntheattentionofORcommunity.Itsgreatsuccesscanbeattributedtothefactthatitisaveryinterestingproblembothfromthepracticalandtheoreticalpointsofview.Regardingthepracticalpointofview,thedistributionprobleminvolveddefinitelyplaysacentralroleintheefficiencyoftheoperationalplanninglevelofdistributionmanagement,producingeconomicalroutesthatcontributetothereductionofdistributioncosts,offeringsimultaneouslysignificantsavingsinallrelatedexpenses(capital,fuelcosts,driversalaries).ItsImportanceinthepracticallevel,motivatedintensetheoreticalworkandthedevelopmentofefficientalgorithms.
FortheproblembyacademicresearchersandprofessionalsocietiesinOR/MS,resultinginanumberofpapersconcerningthedevelopmentofanumberofVehicleRoutingInformationSystems(VRIS)forsolvingtheproblem.TheproblemdiscussedisanNP-hardoptimizationproblem,thatistosaytheglobaloptimumoftheproblemcanonlyberevealedthroughanalgorithmofexponentialtimeorspacecomplexitywithrespecttoproblemsize.Problemsofthistypearedealtwithheuristicormetaheuristictechniques.Researchonthedevelopmentofheuristicalgorithms(Tarantilis&
Kiranoudis,2001,2002a,2002b)forthefleetmanagementproblemhasmadeconsiderableprogresssincethefirstalgorithmsthatwereproposedintheearly60s.Amongthem,tabusearchisthechampion(Laporte,Gendreau,Potvin,&
Semet,2000).Themostpowerfultabusearchalgorithmsarenowcapableofsolvingmediumsizeandevenlargesizeinstanceswithinextremelysmallcomputationalenvironmentsregardingloadandtime.Onthealgorithmicside,timehasprobablycometoconcentrateonthedevelopmentoffaster,simpler(withfewparameters)andmorerobustalgorithms,evenifthiscausesasmalllossinqualitysolution.Theseattributesareessentialifanalgorithmistobeimplementedinacommercialpackage.
Thealgorithmbeyondthesystemdevelopedisoftabusearchnature.Asmentionedbefore,sincethealgorithmscannotrevealtheguaranteedglobaloptimum,thetimethatanalgorithmislefttoproposeasolutiontotheproblemisofutmostimportancetotheproblem.Certainly,thereisatrade-offbetweentimeexpectedfortheinductionofthesolutionanditsquality.Thispartwasimplementedinastraightforwardway.Ifthesystemisaskedbytheusertoproduceasolutionofveryhighqualityinstantly,thenanaggressivestrategyistobeimplemented.Iftheuserrelaxesthetimeofsolutiontobeobtained,thatistosayifthealgorithmislefttosearchthesolutionspacemoreeffciently,thenthereisroomformoreelaboratealgorithms.
Thealgorithmemployedhastwodistinctparts.Thefirstoneisageneralizedrouteconstructionalgorithmthatcreatesroutesofverygoodqualitytobeimprovedbythesubsequenttabuphase.Theconstructionalgorithmtakesintoaccountthepeculiaritiesoftheheterogeneousnatureoffleetandthedesireoftheusertousevehiclesofhisowndesire,ownedorhired,accordingtohisdailyneeds.
TheGeneralizedRouteConstructionAlgorithmemployed,isatwo-phasealgorithmwhereunroutedcustomersareinsertedintoalreadyconstructedpartialsolutions.Thesetofpartialsolutionsisinitiallyempty,andinthiscaseaseedrouteisinsertedthatcontainsonlythedepot.Rivalnodestobeinsertedarethenexamined.
Allroutesemployedinvolvesingleunroutedcustomers.Theinsertionprocedureutilizestwocriteriac1(i,u,j)andc2(i,u,j)toinsertanewcustomerubetweentwoadjacentcustomersiandjofacurrentpartialroute.Thefirstcriterionfindsthebestfeasibleinsertionpoint(i*,j*)thatminimizestheClarkandWrightsavingcalculationforinsertinganodewithinthisspecificinsertionpoint,
C1(i,u,j)=d(I,u)+d(u,j)-d(I,j)
(1)
Inthisformula,theexpressiond(k,l)standsfortheactualcostinvolvedincoveringthedistancebetweennodeskandl.TheClarkandWrightsavingcalculationintroducedinthisphaseservesasanappropriatestrongintensificationtechniqueforproducinginitialconstructionsofextremelygoodquality,acomponentofutmost
necessityintabuimprovementprocedure.
Thesecondphaseinvolvestheidentificationoftheactualbestnodetobeinsertedbetweentheadjacentnodepair(i*,j*)foundinthefirstphase(Solomon,1987).Fromallrivalnodes,theoneselectedistheonethatmaximizestheexpression
C2(i*,u,j*)=[d(0,u)+d(u,0)]-C1(i*,u,j*)
(2)
where0denotesthedepotnode.Theexpressionselectedisthetravellingdistancedirectlyfrom/tothedepotto/fromthecustomerandtheadditionaldistanceexpressed
bythefirstcriterion.Inall,thefirstphaseoftheconstructionalgorithmseeksforthebestinsertionpointinallpossiblerouteseedsandwhenthisisdetected,theappropriatenodeisinserted.Ifnofeasiblenodeisfound,anewseedroute,containingasingledepot,isinserted.
Thealgorithmiteratesuntiltherearenounroutednodes.Itmustbestretchedthatthewayroutesarefilledupwithcustomersisguidedbythedesireoftheuserregarding
theutilizationofhisfleetvehicles.Thatistosay,vehiclesaresortedaccordingtothedistributionandutilizationneedsofthedispatcher.Vehiclestobeusedfirst(regardingtousercostaspectsandvehicleavailability)willbeloadedbeforeothersthatareoflowerimportancetotheuser.Typically,allusersinterviewedexpressedthedesireforthe