Estimate Activity Duration using Three‐Point Estimates (PERT)
The accuracy of the activityMethods to estimate task and activity duration. Read more ... » duration estimateMethods to estimate task and activity duration. Read more ... » can be improved by considering estimation uncertainty and riskWhy Project management and project management plan. Read more ... ».This concept originated with the Program Evaluation and Review Technique PERT.
Pert Definition According to Wikipedia The Program (or Project) Evaluation and Review Technique, commonly abbreviated PERT, is a statistical tool, used in project managementTop 10 steps you should do to be a successful planning engineer. Read more ... », that is designed to analyze and represent the tasks involved in completing a given project. First developed by the United States Navy in the 1950s, it is commonly used in conjunction with the critical path methodCost Management for Engineers-Cost Terms. Read more ... » (CPM).Advertisement
PERTتقدير فترة النشاط باستخدام نظام التقديرات الثلاثية النقط (PERT). Read more ... » (3-Point Estimation Technique) uses three estimates to defineL1-Create,Define Activities and WBS from Bill of Quantities BOQ. Read more ... » an approximate range for an activity’s duration.
There are three types of duration which could be based on some certain conditions or risks, which one you will choose for your scheduleOpen discussion about Members Primavera Time schedules –Real Projects-. Read more ... »? Lets see first what is the different between the three type of durations :
Most likely (tM):
The duration of the activity, given the resources likely to be assigned, their productivityTop 10 steps you should do to be a successful planning engineer. Read more ... », realistic expectations of availability for the schedule activity, dependencies on other participants, and interruptions.
The activity durationCreate Gantt Chart and cash flow using excel with sample file. Read more ... » is based on a best‐case scenario of what is described in the most likely estimate.
The activity duration is based on a worst‐case scenario of what is described in the most likely estimate.
3-Point Estimate Formula:
The Optimistic Time (a) :
The Most Likely Time (m):
The Pessimistic Time (b):
T exp =(a+4m+b)/6
PERT analysis calculates an Expected (tE) using a weighted average of these three estimates:
An activity has 3 estimates, provided below:
Optimistic = 10 days
Pessimistic = 30 days
Realistic = 15 days
What is the three point estimate for this activity?
T (Time)= (10+(4*15)+30)/6 = 16.66 day
16.66 days is the suitable duration to put in your schedule not 10 nor 30 . I hope you enjoyed this Project ManagementWhy Project management and project management plan. Read more ... » Three-Point Estimate.