Tips on using this forum..

(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?

(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.

Primavera Risk Analysis - Getting the absolute minimum and maximum

3 replies [Last post]
Alireza R
User offline. Last seen 20 weeks 2 days ago. Offline
Joined: 20 Feb 2020
Posts: 2
Groups: None

Hi all,


I have a very detailed risk analysis for my project (different risks, different uncertainties with different distributions,...). And now I would like to see the "absolute" minimum and maximum end dates.

Ofcourse since Monte Carlo Analysis is based on random iterations, I can never say with certainty what the shortest project duration is (think extremely happy flow, all uncertainties getting the minimum durations). I get the minimum from OPRA but next time I run the simulation I might get a new minimum (or maximum).

I know this defies the purpose of statistical nature of Monte Carlo but I am wondering whether there is an option to first find the extreme values on the both ends of the spectrum and then fill in the between (something like a polygraph, jumping to the both extremes first and then filling the values the fall within those two).


I have tried increasing the iterations to 20000 (higher than 99% confidence level) but this still is not hitting the sweet spots.


any ideas?





David Kelly
User offline. Last seen 7 weeks 4 days ago. Offline
Joined: 19 Oct 2004
Posts: 583
No Oracle customers even know that is missing, Vladimir.


Spider Project creates optimistic and pessimistic project versions.

Optimistic uses optimistic estimates of project parameters and includes risk events with more than 90% probabilities to occur, pessimistic uses pessimistic estimates of project parameters and includes all risk events.

David Kelly
User offline. Last seen 7 weeks 4 days ago. Offline
Joined: 19 Oct 2004
Posts: 583
As you admit yourself, your question kind of undermines the whole ethos of probabilistic analysis. There are no “deterministically” best and worst dates following a probabilistic analysis. You could choose to calculate and save the 1% and 99% percentiles, and ensure you are using Monte Carlo and not Latin Hypercube sampling, both of which you will find in the Risk Analysis Options.