http://www.alsenosy.com | http://www.professionalengineers.usastheratioofthecosttofinishtheoutstandingworktotheremainingbudget.TCPIisthecalculated
costperformanceindexthatisachievedontheremainingworktomeetaspecifiedmanagement
goal,suchastheBACortheEAC.IfitbecomesobviousthattheBACisnolongerviable,theproject
managershouldconsidertheforecastedEAC.Onceapproved,theEACmayreplacetheBACinthe
TCPIcalculation.TheequationfortheTCPIbasedontheBAC:(BAC–EV)/(BAC–AC).
TheTCPIisconceptuallydisplayedinFigure 7 – 13.
TheequationfortheTCPIisshowninthelowerleftastheworkremaining(definedastheBACminus
theEV)dividedbythefundsremaining(whichcanbeeithertheBACminustheAC,ortheEACminus
theAC).
IfthecumulativeCPIfallsbelowthebaseline(asshowninFigure 7 – 13 ),allfutureworkofthe
projectwillneedtobeperformedimmediatelyintherangeoftheTCPI(BAC)(asreflectedinthetop
line ofFigure 7 – 13 ) tostaywithin the authorizedBAC.Whether thislevel ofperformance is
achievableisajudgmentcallbasedonanumberofconsiderations,includingrisk,schedule,and
technicalperformance.ThislevelofperformanceisdisplayedastheTCPI(EAC)line.Theequationfor
theTCPIbasedontheEAC:(BAC–EV)/(EAC–AC).TheEVMformulasareprovidedinTable 7 – 1.
Equation:TCPI=(BAC–EV)/(BAC–AC)
- Answer: A.
PMBOK®Guide,page 264 ,Section 7. 4. 2. 2
Forecasting
Astheprojectprogresses,theprojectteammaydevelopaforecastfortheestimateatcompletion
(EAC)thatmaydifferfromthebudgetatcompletion(BAC)basedontheprojectperformance.Ifit
becomes obvious that the BAC is no longer viable, the project manager should consider the
forecastedEAC.ForecastingtheEACinvolvesmakingprojectionsofconditionsand eventsinthe
project'sfuturebasedoncurrentperformanceinformationandotherknowledgeavailable atthe
timeoftheforecast.Forecastsaregenerated,updated,andreissuedbasedonworkperformance
data (Section 4. 3. 3. 2 )That are providedas the project is executed.The work performance
informationcoverstheproject'spastperformanceandanyinformationthatcouldimpacttheproject
inthefuture.
EACsare typically basedon the actual costsincurred forworkcompleted, plusan estimateto
complete(ETC)theremainingwork.Itisincumbentontheprojectteamtopredictwhatitmay
encountertoperformtheETC,basedonitsexperiencetodate.
Theprojectmanager'smanualEACisquicklycomparedwitharangeofcalculatedEACsrepresenting
variousriskscenarios.WhencalculatingEACvalues,thecumulativeCPIandSPIvaluesaretypically
used. While EVMdata quickly provide many statistical EACs, only three of the more common
methodsaredescribedasfollows:
EACforecastforETCworkperformedat thebudgetedrate.ThisEACmethod acceptsthe actual
projectperformancetodate(whetherfavorableorunfavorable)asrepresentedbytheactualcosts,
and predicts thatall futureETC workwill be accomplished at the budgetedrate. Whenactual
performance is unfavorable, the assumption that future performance will improve should be
acceptedonlywhensupportedbyprojectriskanalysis.Equation:EAC=AC+(BAC–EV(
Equation:ETC=EAC–AC