Role of Delay AnalysisTechniques on Contract Scheduling ByMark Smith MEM MBA-00000000 Abstract Delaysareprevalentinconstructionprojects.Theyarecostlyforpartiesinvolvedifnotproperlyand timelydealtwith.However,probingwhoisculpableforthedelaysisadifficulttask.Anumberofdelay claimanalysistechniquesexistwithvaryinglevelsofcomplexityandresultsaccuracy.Thispaper elaboratesthedistinctadvantagesanddisadvantagesofeachmethodandotherderivativetechniques.In theprocess,acomprehensiveunderstandingofthereliabilityextentandsituationalusabilityofeach scheduleanalysistoolareobtainedwhileidentifyinggapsthatcanleadtofurtherresearch.Thetime impactanalysis(TIA),underpinnedbycriticalpathmethod(CPM),isthewidelyacceptedmethod mainlybecauseofitshighdegreeofaccuracyrelativetotheothertools.However,thistechniqueisalso themostcomplicatedtouse.Givenso,schedulingsoftwarePrimaveraisinvaluableinundertakingthe complexityofTIAifproperlycarriedout.Thus,afutureresearch,addressingtheidentifiedresearch questions,onapplyingTIAwithPrimaverapragmaticallydepictinghowschedulingisimplementedin projects couldguide practitionerson meticulous practiceof themethod. 1. Introduction Delayshavebeenacommonoccurrenceinconstructionprojects(Alkassetal.1995;Arditi& Pattanakitchamroon2006;Braimah2013;Zaneldin2006).Timelycompletionisdifficulttoattaindue tothecomplexity,unpredictability,involvementofmultiplepartiesandotheruncontrollablefactors characteristicofaproject(Kartam1999).InastudyconductedbyKumaraswamy&Yogeswaran (2003),ofthe67engineeringprojectsinvestigatedinHongKong,about85%suffereddelays.Similarly, Assaf&Al-Hejji(2006)foundthat70%ofconstructionprojectsthey havesurveyedinSaudiArabia neededextendedperiodoftimetobecompleted.ThesametrendwasmanifestedinJordanwherein almost82%outofthe130projects probedwent throughdelays(Al-Momani2000).These establish the global pattern to which construction projects areimplemented against thepredefined completion date. A number ofresearchersindicate that one ofthe main reasons fordelays is the changeorder initiated by owners. Othercausespointtoinefficientproductivityofthecontractorsandinclementweather(Al- Momani2000;Assaf&Al-Hejji2006;Odeh&Battaineh2002;Zaneldin2006).Assaf&Al-Hejji (2006)wenttodiginfurthertotheextentoftenderingstage andreasonedthattheengineering conventionalpracticeofawardingtheprojecttothelowestbidderwithoutdueregardtothetechnical capabilityofthecontractoristhecauseofdelays.ForRooke,Seymour&Fellows(2004),bigtime contractorsintentionallysubmitbidsevenatalossiftheyforeseethelikelihoodofgeneratingprofits fromdelayclaims.Intheprocess,itcreatesbarrierstosmallandentry-levelplayersbecauseonlylarge contractorscanemploypersonnelexpertinmanagingclaimswhileavoidingownresourcestobecoming idle. Projectdelaysresulttocostimplicationsforboththeownerandthecontractor(Alkassetal.1995; Householder&Rutland1990).Theyareawareofthehighcostsassociatedindelayclaimsespeciallyin litigation(Kartam1999).Differentfactorscontributetoprojectdelays,hence,theneedtosystematically dissectandidentifythetypeandtheculpableparty.Ownerstendtoblamecontractorsasfaultedthe delaysandvice-versa(Ibbs&Nguyen2007).Anumberofdelayclaimanalysistechniquesexistwith varyinglevelsofcomplexityandresultsaccuracy(Gothand2003).However,thereisnouniversally acceptedmethod.Themethodofusedependslargelyontheavailableprojectinformation,scheduling software capabilityand the effortandcost allottedfortheanalysis(Arditi &Pattanakitchamroon 2006). Though,researchersandpractitionersalikeconcurthatthemostcomplicatedcriticalpathmethod(CPM) of timeimpact analysis (TIA)yield the most accurate delayclaims result relative to othertechniques. Thispaperdiscussesthedifferenttechniques,highlightingtheiradvantagesanddisadvantages,usedin analyzingconstructiondelaysdelvingonplausiblegapsthatcanserveasfoundationsforfutureresearch on similarfield. 2. LiteratureReview Delays on contract completion in construction canbe attributed as causedbythecontractor,ownerorbyathirdparty.Contractor-causeddelays, especially non-excusabledelays(NED),generallyresult inlowproductivity.Dependingonwhatisstipulatedinthe contract,thecontractormightbeliabletopaytheownerliquidateddamages.Owner-causedisexcusable compensabledelays(ECD):forinstance,aninstructionbytheownerforadditionalworks,thereby,an entitlementtopaidextensionoftimeforthecontractor.Inthecausationbyathirdparty,neitherthe ownernorthecontractorisatfault(i.e.,duetobadweather).However,inthisexcusablenon- compensabledelays(ENCD),thecontractorisgrantedadditionaltimetocompletetheprojectliftingtheliquidateddamagesbutwithoutadditionalcompensationfromtheowneraswell(Kartam1999).The classificationofdelaysistheunderlyingprincipleontowhichthecostandtimeimplicationstothe construction scheduleare assessed andanalyzed. Differentconstructiondelayanalysistechniquesareavailableforpractitionerstouse.Inincreasingorder ofaccuracyandcomplexity,thecommonlyusedare:(1)Globalimpact;(2)Netimpact;(3)Impactedas- planned;(4)Collapsingas-built;(5)Windowanalysis;and,(6)Timeimpactanalysis(Alkassetal.1995; Arditi&Pattanakitchamroon2006).Inglobalimpacttechnique,delays aresimplysummed-upwiththe assumptionthateachdelayimpactsinthesamemagnitudetheoverallschedule.Calculateddelaysare thereforebloated.Thenetimpacttechniqueisastraightforwardcomparisonoftheas-plannedandas- builtschedules.Overalldelayisdeterminedbythedifferenceinthefinishdatesofthetwoschedules. Responsibleforthedelaysisthenassessedandidentified.Thereisnoneedtohaveintermediary scheduleswhichistheapparentadvantageofthismethod.However,itlacksthein-depthanalysisofthe dynamismof thecriticalpath(Arditi&Pattanakitchamroon 2006).The project critical path determines itsoverallduration.Itcontinuouslychangeswithscheduleupdatesduringthecourseoftheconstruction. Delayingacriticalactivityprolongstheprojectduration(Gothand2003).Schedulingbycriticalpath method(CPM),initiallyforplanningandmonitoringofconstructionprojects(Householder&Rutland 1990),isthewidelyusedapproachindelayanalysisandclaimsdisputeresolution(Householder& Rutland1990;Ibbs&Nguyen2007).Theimpactedas-plannedtechniqueistheeasiestoftheknown schedulingmethodstousebuttheleastreliable.Onlytheas-plannedscheduleisneededanddelays causedbytheownerisinsertedintotheschedule.Thechangeinthescheduledurationistakenasthe delayattributedtotheowner.ThoughbasedonCPM,thetooldoesnottakeintoaccountchangesin the criticalpath,sequenceofwork,actualdurationandeventsreflectiveoftheactualprojectimplementation astheanalysisdependsonlyonthepre-establishedbaselineschedule(Arditi&Pattanakitchamroon 2006).AsGothand(2003)pointsout,normally,scheduleanalysisundergoesstrictexaminationbythe owneranditscredibilityisenforcedbyadministeringaswellthecontractor’sowndelayevents.The collapsingas-builttechniqueaddressestheshortfalloftheas-plannedtoolbyconsideringtheactualseries ofeventsandactivitiesthathavetranspiredduringtheconstructionperiod.Thisisthepreferredmethod intheabsenceoftheas-plannedschedule.However,itdoesnotcovertheconstantshiftingofthecritical pathatstagesduringprojectexecution(Arditi&Pattanakitchamroon2006).Thewindowanalysisand thetimeimpactanalysis(TIA)techniquesarebasedonCPMapproach.Inbothtechniques,delaysare addedtothecontemporaneousschedule.Linksamongstactivitiesareadjustedtoreflecttheactual work executionsequence.Thedynamismofthecriticalpathisconsideredinthescheduleexamination.The techniquesproducethemostaccurateresultsrelativetotheotheraforementionedmethods.However, thecomprehensiveandscientificapproachentailedbythetechniquesmakesthemalsothemostdifficult toundertake.Theirdistinctionisthatwindowanalysistechniqueisusedforvaluingaftertheprojecthas beencompletedwhileTIAisapplicableforforward-lookinganalysisorwhileconstructionisstillin operation (Arditi &Pattanakitchamroon 2006; Braimah 2013; Gothand 2003; Hegazy&Zhang2005). OthermethodshavebeendevelopedtotackletheperceivedweaknessesoftheTIAorwindowanalysis techniquewhilebuildingontoitsapparentadvantageofaccuracylevel.Fan(2011)introducedthe modifiedtimeimpactanalysis(MTIA)techniquewhereinanewschedulerepresentedonlybythe affectedactivitiesistobecreatedfromtheworkingprogram.Thiswillsimplifythepresentationand discussionofthescheduleanalysis. However,in choosingactivitiestoinclude,relationships arealtered andincorrectorincompleteactivitiesmightbeselectedas well,altogether, modifyingthe essenceofthe originalschedule.MTIAcanworkbestinsupportofthecompleteTIAschedulebutnotasareplacement. Hegazy&Zhang(2005),claimingthatresultsoftraditionalwindowanalysisforthesameschedule varydependingonthesizeofthe‘window,’proposedthemodifiedwindowanalysis.Theirsolutionwas day-to-dayanalysis(insteadofweeklyormonthlywindowsize)andrecording onadailybasis informationtotheirproposed‘intelligentbarchart’spreadsheet.Theapparentdisadvantageofthis methodisthearduoustaskofloggingprogressdataeachdaycomprised,typically,ofhundredsof activities,whichistimeconsumingandisdifficulttoattaininpractice.Ibbs&Nguyen(2007) contendedthatwhileanumberofstudiespointedtotheneedtoincluderesourcerequirementsintothe schedule,noneoftheknowntechniquesconsiderresourceallocationindelayanalysis.Theyarguedthat pragmatically,siteprogressoutputisverymuchdependentonallocatedresources,thereby,drivingthe delayoraccelerationofthework.Bylevelingthedemandofresources,theyhavedemonstratedthat for thesameschedule,windowanalysiswithconsiderationofresources(RWA)provideddifferentresults comparedtothetraditionalversionofthesamemethod.Thedifficultyofimplementingthismethodlies inthecorrectassignmentofresources,intermsoftrade,typeandquantity,toeachandeverysite deliverable activitiesand monitoringtheactualallocation.Inadditiontothis,theiranalysisassumes the exclusiveuseofaparticularresourcetoanactivitywhileinreality,resourcesaresharedamongseveral activitiesdependingon availabilityat aparticulartime.Meanwhile, Nguyen&Ibbs(2008) contended thatfloatownership,logicchangesandresourceallocationshouldallbetakenintoaccountinthe analysis: hence, theirproposed FLORA methodstructured on window analysis method. Effects ofeach factorareillustratedintheirliterature.Thetotalfloatistheamountoftimethatanactivitycanbedelayed withoutaffectingtheprojectcompletiondate(Nguyen&Ibbs2008).Understandingitsvitalityin assessingdelays,floatownershipisnormallypredefinedinthecontract(Arditi&Pattanakitchamroon 2006). Householder &Rutland(1990)stressthat, in a typicalcontract, itwould bebeneficial forboth theownerandthecontractorifthelatterownsthefloat.Thiswillallowthecontractortheflexibilityto properlymanagetheprojectandtheleewaytoapportionitsownresourcesasdictatedbyprevailing circumstances.Theconventionalwindowanalysisrequiresadjustingactivityrelationships,whenever necessary,toreflectactualsiteimplementation.Therationaleofincludingresourceallocationinthe scheduleanalysismethodaspurportedbyNguyen&Ibbs(2008)isthesameasthatestablishedbyIbbs &Nguyen(2007).Overall,FLORAmethodaddscomplexitytowindowanalysisbyaddingdimensions whereinasimple clausein the projectcontract canbesolved while havingsame attention as RWA. 3. Evaluation Itisimperativethattypesofconstructiondelaysandtheirattribution,whethertotheowner,contractor orboth,beunderstoodfirstbeforeany detailedanalysisiscarriedout.Anumberoftechniquesexistto assessdelayclaimswithvaryingcomplexityandaccuracy.Thehighrisksandcostsassociatedwith delayclaims,especially,ifitreachesthelitigationstage,implicatetherequisiteneedthatonlycredible methodologybeusedintheprocedure.Unlessstatedotherwiseinthecontract,accordingtoBraimah (2013),thetechniqueofchoiceishighlydependentontheavailableprojectinformation.Alkassetal. (1995)relatethat,ifnotproperlymanaged,collatingandscrutinizingprojectdocumentationalonecan take severalmonthsalready.Thismeansadditionalexpensestoeithertheowner,contractororbothfor the extraconsultation fees. Arditi &Pattanakitchamroon(2006)reportthatresearchersandpractitionerstheyhavecovered reviewingliteratureprefertheuseofTIA.Thisissupportedbyindependentstudiesconductedby Braimah(2013),andKumaraswamy&Yogeswaran(2003).TIA, asmentioned, is acomplicatedtool to operate butyield the most credibleresults. However, computer technologyadvancements havemade itpossibletodaytoanalyzeintricatedetailedschedules(Gothand2003).Projectmanagementsoftware suchasPrimavera,ifexploitedproperly,isinvaluableinscrutinizingschedules.It,thoughinitselfis alsocomplicatedtouse,hasbeenextensivelyusedintheUnitedStates(Braimah2013).Whileplenty has been written about TIA, a written exposition on its practical use with scheduling software, particularlyPrimavera,isnotreadilyavailable.Moreover,TIAdoesnotconsidertheinfluenceofproject resourceallotmentvialevelingintheanalysis.Thiscontradictstherealityofthedirectimpactofthe assignedresourcesonconstructionprogress.Ibbs&Nguyen(2007)havedemonstratedtheimpactof resourcesonconventionalTIA.Nguyen&Ibbs(2008)pointedtootherfactorsthatmustbeconsidered indelayanalysissuchasfloatownershipandlogicchanges,inadditiontoresourceallocation.They haveintroducedthemethodFLORAwithTIAservingasthebackbone.Floatownershipcanbe addressedattheonset oftheprojectthroughcontractclauses.HouseholderandRutland(1990) recommendthatownershipofthefloatbeonthesideofthecontractorforleastinterruptionandflexibility inmanagingtheproject.Changingactivityrelationshipsduringthecourseoftheconstructionisalready intrinsicofTIA.Ibbs&Nguyen(2007),andNguyen&Ibbs(2008)demonstratedtheimpactof resourcelevelinginTIAusingasimplenetworkofconstructionactivities.However,inpractice, constructionschedulesarecomprisedofhundredsofactivitieswithmultipleresourcesassignedper activity.TIAaloneisperplexingtooperate, addingthe effect of resourcesmakesit evenmoredifficult tooperate.However,Primaverais designed for use inhandlingthe complexity presented by TIA evenfactoring intheresource allotment. Future researchtheninthedirectionofhow TIAshouldbepracticedandhandledwithPrimavera,takingadvantageofthetechnological advancements, is crucialformoreefficientresolution of delayclaims. SinceTIAisconsideredthemostreliablemethodinclaimsanalysis,projectmanagersshouldencourage practicesofproperlymanagingprojectinformationsothatpertinentdataareavailableincasethereisa needforTIA(Arditi&Pattanakitchamroon2006).Thisbeginswithdevelopingawell-prepareddetailed as-plannedschedulewithcorrectlogicalrelationshipsofactivities,realisticduration,workbreakdown toacceptablelevel,sufficientcoveragesofinvolvedactivitiesandsoon.Theprocessinvolvesthe participationofmembersofprojectmanagementteamcontributingtheirknowledge andexpertiseinthe build-upoftheschedule(Braimah2013).Theplanningengineeristhemostinvolvedinsynthesizing thethoughtsofvariousstakeholderstoformulatetheschedulethathecaneffectivelycommunicateto peopleinasimplisticbutcomprehensibleform(Braimah2013;Gothand2003).Indevelopingthe schedule,Arditi&Pattanakitchamroon(2006)emphasizehowsoftwaresettingscanmakesignificant differenceinthescheduleassessment.Thus,futureexaminationofthecorrectparameterstoconsiderin Primavera(i.e.,whethertoschedulebyretainedlogicorprogressoverride, impactofdifferentcalendars used,programdefinitionoftotalfloat,progressmeasurementtypeandsoon)atthecrucialbuild-upstage of theschedulesuch thatit is TIA-readiedneeds tobeundertaken. TheconceptualapproachofTIAaboundsinliterature.Interestingly,preciseapplicationofTIA withPrimaveraschedulingsoftwaredepictingtheactualstateofconstructionisscantlyavailable.As such,futureresearchtotestthepracticalityandeffectivenessoftheanalysistechniquewithPrimavera couldguidepractitionersonmeticulousexerciseofthemethod.Atthispoint,researchquestionsdrawn are: A. HowisTIAappliedwiththeactualschedulingsoftwarePrimaverathatisnormallyutilizedin construction projects? B. WhatshouldbethesettingsinPrimaveraandthepointersfortheplanningengineertoconsider inthegamutofconstructionschedulingfrombuild-up,managementandcompletionstagesofthe project such that theschedule is capableforTIA? C. Howcan resource allocation beincorporated in the analysis? D. Arethereanyotherderivatetechniquesthatcanbedevelopedwithacceptablelevelofaccuracyat least equal to that with TIA? 4. Conclusions Timelycompletionofprojectsisdifficulttoaccomplishinconstruction.Contractorsandownersare facedwiththedauntingtaskofsubmittingcredibledelay analysisandassessing claims,respectively,to determinethecausationextentofculpableparties.CPM-basedTIAiswidelyregardedasthescheduling techniquethatcanbestdepicttheconditionsthattranspiredduringthecourseoftheconstruction. However,thecomplexityofundertakingthetechniquehasresultedtopractitionersresortingtoless crediblemeansofexaminingdelays.SchedulingsoftwarePrimaverahasbeendesignedtohandlethe intricacyofthemagnitudeposebyTIA.Thesoftware,initself,isalsocomplicatedtouseandcould provideerroneousresultsifnotproperlymanaged.ConceptualandsimpleapplicationsofTIAhavebeen coveredinanumberofliterature.Interestingly,preciseapplicationofthetechniquewithPrimavera depictingthe actual stateof construction is scantlyavailable.As such, further research evolvingaround theconsiderationstoexploittheavailablesoftwareforproperimplementationofTIAinthegamutof constructionschedulingfrombuild-up,managementandcompletionstagesoftheprojectwouldbe beneficial to practitionersonthe meticulous practiceofthis complexbut highlyaccurate method. 5. References Al-Momani,A.H.2000,'Constructiondelay:aquantitativeanalysis',Internationaljournalofproject management, vol. 18, no.1, pp. 51-9. 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