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Proceedingsofthe6thAsia-PacificStructuralEngineeringandConstructionConference(APSEC2006),5–6September2006,KualaLumpur,MalaysiaD-39PROJECTCOSTPERFORMANCEFORECASTINGSYSTEM1SitiRashidahMohdNasiraand2MuhdZaimiAbd.MajidCTMC,FacultyofCivilEngineering,UniversityTechnologyMalaysia,81310-Skudai,Johor,[e-mail],Abstract:Forecastingprojectcostperformanceisaparamountimportanttotheprojectcontrolsprocessinconstructionindustry.Inmakingprofits,today’sconstructionorganizationrequiresanabilitytopredict,wellaheadoftime,projectperformance.Thus,necessaryandtimelycorrectiveactionsneedtobetakenifprojectlaggedoftimeorexceedbudget.Asaconsequence,therehavebeenmanystudiesonthisaspectwhichdeveloptheoriesandmethodstoimprovetheforecastingsystem.Throughacriticalreviewofforecastingmethodapproaches,anumberofissuesarehighlightedthatconcernofthetypesofforecastingapproach,forecastingprojectcostperformanceatcompletion,costvariancesinprojectperformance,othercriticalparametersofprojectperformancetobeincorporatedalongwithcostandineffectivemethodsingeneratingreliableandtimelyresultsandthereforeprovidingearlywarningofcostperformanceoverruns.Also,itprovidesfundamentalforforecastingsystemdesignedforadaptabilityinachallengingenvironmentandfocusedthroughoutonthedeliveringsuccessfulproject.Keywords:Construction,ProjectCostPerformance,Forecasting.1.INTRODUCTIONForecastingperformanceisoneofthemostchallengingtasksinpredictingwhethertheprojectwillbesuccessful.Inturn,thiswilldependontheabilityoftheprojectmanagertopredict,wellaheadoftime.Inattemptingtoestablishthereliableforecastingsystem,itisrequiredtodevelopaforecastingtoolswhichcapableindealingwithvariabilityexistinginconstructionoperations.Assuch,thishasstillbeenaburdentoprojectmanagertodeterminetheaccuratedataasearlyaspossiblewheretheprimaryimportantofforecastingsystemis,itshouldbeabletopredictvariancedataatanyfuturetimeandatcompletionandthusprovideanearlywarningofperformanceoverruns.Often,projectvariablesdifferfromtimetotimethroughouttheconstructionoperationwhichusuallyunacceptabletomoststakeholder.Thus,areliableforecastingsystemshouldprovideprojectmanageranaccurate,unbiased,timelyandstablesystem.Inessence,however,accurateprojectperformanceforecastsaredifficulttoproducewhenconsideringtheimpactofsomefactorssuchasmaterialdelays,scopedeviation,poorproductivity,unforeseenscopechanges,andadverseweatherconditions.Mostofthecurrentsystemsarenotdesignedtoincorporatethisinputintheformofajudgmentalinputfromtheuserandconsequentlycouldleadtoinaccurateresults.Theaimofthispaperisthustoprovideacriticalsummaryofthestatusofforecastingsystem,highlightingtheimplicationsofthestate-of-the-artforbothresearchandpractice.Consequently,keyissuesthathavedriventhedevelopmentofthetheoreticalapproachesarereviewedalongsidethepracticaldifficultiesthatarisewhenattemptingtoapplyforecastingsysteminpractice.Thepaperbeginsbysynthesizingtheperceptionsthatsurroundforecastingsysteminordertostatethefundamentalgoalsoftheapproach.Thesegoalsprovideabasisforassessingthedevelopmentinforecastingstandards,whicharethen,canbeusedasadatumforfutureresearchpurpose.Adetailedcriticalanalysisofforecastingsystemisalsopresentedandanumberofissueshighlightedthatconcern(a)thetypesofforecastingapproach,(b)forecastingprojectcostperformanceatcompletion(c)costvariancesinprojectperformanceProceedingsofthe6thAsia-PacificStructuralEngineeringandConstructionConference(APSEC2006),5–6September2006,KualaLumpur,MalaysiaD-40(d)othercriticalparametersofprojectperformancetobeincorporatedalongwithcost,(e)ineffectivemethodsingeneratingreliableandtimelyresultsandthereforeprovidingearlywarningofperformanceoverruns.Lastly,thepaperconcludesbypresentingcoherentrecommendationsonhowforecastingmanagementsystemcanbestbeusedinpractice.2.ANOVERVIEWONFORECASTINGSYSTEMINCONSTRUCTIONINDUSTRYThenatureofconstructionindustryistobeprofitableinextremelycompetitiveenvironment.Morespecifically,theconstructionenvironmentiscontinuouslychangingandresultedtouncertainvariableinprojectdata.Asaconsequence,ProjectManagerfacedwithperformanceproblemindeterminingtheaccurateprojectperformance.Inattemptingtogainbetterprofits,ProjectManagerneedstomaketimelyandinformeddecision.However,today’sdeficienciesinmonitoringandcontrolofprojectoperationunableProjectManagertomanageprojecteffectivelyandresultedtomajorcauseofprojectfailure.Whencontrollingprojectperformance,ProjectManagershouldnotonlymonitorcostandtimevariancesforactualprojectprogress,butalsotoproperlyestablishtheactualprojectstatusbasedonobjectivepredictionsoffinalprojectperformance.Atcompletionprojectperformancecanbepredictedbycomparingestimatesofplannedtotalbudgetandfinaldurationwiththeirrespectivemostlikelyforecastedvalues(Ahujaetal.1994).This,however,arenecessaryforProjectManagertodetermineifcorrectiveactionsarerequiredtominimizetheexpectedvariancesfromplannedperformanceThus,forecastingisneededtopredicttheprojectperformanceatcompletionbasedoncurrentperformance.2.1SignificanceofProjectForecastingintheConstructionIndustryInreality,theoriginales