Calculate PERT (Program Evaluation Review Technique) estimates for project management.
Task Scenarios
Estimates
Expected Duration16.67hours/days
Standard Deviation (Risk)3.33
Variance11.11
95% Confidence Range
10.0 - 23.3
About this calculator
Overview
PERT uses three estimates (optimistic, most likely, pessimistic) to calculate expected duration. Weighted average gives more weight to most likely. Essential for project planning and risk assessment.
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Pro Tips
Optimistic: best case scenario.
Most likely: realistic estimate.
Pessimistic: worst case scenario.
Standard deviation = (Pessimistic - Optimistic) / 6.
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Fun Facts
"Developed by US Navy (1958) for Polaris missile."
"4-2-1 weighting reduces estimate bias."
"Used with Critical Path Method (CPM)."
"95% confidence: Expected ± 2× Standard Deviation."
