Effect of Statistical Distributions on Success Rates
Moderator: Intaver Support
Effect of Statistical Distributions on Success Rates
Does the type of statistical distribution matter when we calculate success rate due to deadline?

 Posts: 823
 Joined: Wed Nov 09, 2005 9:55 am
Re: Effect of Statistical Distributions on Success Rates
Yes, the success rate can be affected if the distributions have significantly different probability density at the deadline. In the example below, there are two tasks with the exact same estimates, but the statistical distributions are different: Triangular and Uniform with deadlines set at 6 days, one more than the base estimate of five. We can see that Task 1 has a much higher success rate than Task 2. This is because the probability or area under the curve at ≥ 6 days is greater with the Uniform Distribution and therefore the success rate of finishing at or before 6 day duration is less for Task 2.
Statistical distribution for duration for task 1 is Trangular.
Statistical distribution for duration for task 2 is Uniform
Statistical distribution for duration for task 1 is Trangular.
Statistical distribution for duration for task 2 is Uniform
Intaver Support Team
Intaver Institute Inc.
Home of Project Risk Management and Project Risk Analysis software RiskyProject
www.intaver.com
Intaver Institute Inc.
Home of Project Risk Management and Project Risk Analysis software RiskyProject
www.intaver.com