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Primavera Risk Analysis - Getting the absolute minimum and maximum

3 replies [Last post]
Fri, 2020-02-21 10:54
Alireza R
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Joined: 20 Feb 2020
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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?

 

br.

AR

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Replies

Thu, 2020-02-27 15:46
#1
David Kelly
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Joined: 19 Oct 2004
Posts: 630
Groups: Petro-Chem / Oil & Gas
No Oracle customers even know that is missing, Vladimir.
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Thu, 2020-02-27 11:41
#2
Vladimir Liberzon
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Joined: 5 Feb 2001
Posts: 2753
Groups: Accreditation Editors, Board of Advisors, Civil Engineering, GPCCAR Editors, Petro-Chem / Oil & Gas, Regional Representatives, Spider Project Team, TURNAROUND & SHUTDOWN (T/A & S/D)

David,

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.

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Thu, 2020-02-27 10:54
#3
David Kelly
User offline. Last seen 2 years 16 weeks ago. Offline
Joined: 19 Oct 2004
Posts: 630
Groups: Petro-Chem / Oil & Gas
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.
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