PERTProgramEvaluationandReviewTechniqueAnEstimatingMethod•Usesthreeestimates–Optimistic,MostLikelyandPessimistic•CalculatesestimateusingaweightedaverageO+4(ML)+P6Example•AssumethefollowingestimatesforcompletinganActivity–Optimistic=30minutes–MostLikely=45minutes–Pessimistic=90minutesCalculatethePERTEstimate•CalculatesestimateusingaweightedaverageO+4(ML)+P630+(4x45)+90=300=5066Probability•Whatistheprobabilityofcompletingtheactivitywithinagiventimeframe?•MustapplysomestatisticalanalysisStandardDeviation•Representsameasureofdispersionofthepoints.=SD=P–O6SD=90–30=60=1066σNormalDistribution•Assumesasymmetricaldistributionaboutthemean.NormalDistribution•PERTEstimate=Mean=50501SDfromMean•PERTEstimate=Mean=5050604068%2SDfromMean•PERTEstimate=Mean=5050604068%307095.5%3SDfromMean•PERTEstimate=Mean=5050604068%307095.5%802099.7%3SDfromMean•Chanceofcompletingtheactivityin50minutes50604068%307095.5%802099.7%50%0%100%3SDfromMean•Chanceofcompletingtheactivityin60minutes50604068%307095.5%802099.7%3SDfromMean•Chanceofcompletingtheactivityin60minutes50604068%307095.5%802099.7%50%68%3SDfromMean•Chanceofcompletingtheactivityin60minutes50604068%307095.5%802099.7%100%-68%=32%68%3SDfromMean•Chanceofcompletingtheactivityin60minutes50604068%307095.5%802099.7%100%-68%=32%68%16%16%3SDfromMean•Chanceofcompletingtheactivityin60minutes50604068%307095.5%802099.7%68%+16%=84%68%16%16%
