04_4_PERT_Presentation.ppt

PERT,Program Evaluation and Review Technique,An Estimating Method,Uses three estimatesOptimistic,Most Likely and PessimisticCalculates estimate using a weighted average O+4(ML)+P 6,Example,Assume the following estimates for completing an ActivityOptimistic=30 minutesMost Likely=45 minutesPessimistic=90 minutes,Calculate the PERT Estimate,Calculates estimate using a weighted average O+4(ML)+P 6 30+(4 x 45)+90=300=50 6 6,Probability,What is the probability of completing the activity within a given time frame?Must apply some statistical analysis,Standard Deviation,Represents a measure of dispersion of the points.=SD=P O 6 SD=90 30=60=10 6 6,Normal Distribution,Assumes a symmetrical distribution about the mean.,Normal Distribution,PERT Estimate=Mean=50,50,1 SD from Mean,PERT Estimate=Mean=50,50,60,40,68%,2 SD from Mean,PERT Estimate=Mean=50,50,60,40,68%,30,70,95.5%,3 SD from Mean,PERT Estimate=Mean=50,50,60,40,68%,30,70,95.5%,80,20,99.7%,3 SD from Mean,Chance of completing the activity in 50 minutes,50,60,40,68%,30,70,95.5%,80,20,99.7%,50%,0%,100%,3 SD from Mean,Chance of completing the activity in 60 minutes,50,60,40,68%,30,70,95.5%,80,20,99.7%,3 SD from Mean,Chance of completing the activity in 60 minutes,50,60,40,68%,30,70,95.5%,80,20,99.7%,50%,68%,3 SD from Mean,Chance of completing the activity in 60 minutes,50,60,40,68%,30,70,95.5%,80,20,99.7%,100%-68%=32%,68%,3 SD from Mean,Chance of completing the activity in 60 minutes,50,60,40,68%,30,70,95.5%,80,20,99.7%,100%-68%=32%,68%,16%,16%,3 SD from Mean,Chance of completing the activity in 60 minutes,50,60,40,68%,30,70,95.5%,80,20,99.7%,68%+16%=84%,68%,16%,16%,