HomeTechniques and Tips@RISK PerformanceSimulation Speed of @RISK with Microsoft Project

9.3. Simulation Speed of @RISK with Microsoft Project

Applies to:
@RISK 6.x/7.x, Professional and Industrial Editions
@RISK for Project, all releases

I recently upgraded Microsoft Project 2003 to a newer version, and my simulations seem to take longer to run. Do I need to change some setting?

Recalculation speed has changed between versions of Microsoft Project, and this impacts the run times of @RISK simulations. Why? Because for each iteration of a simulation @RISK must fully recalculate Microsoft Project.

Recalculations are fastest in Microsoft Project 2003 and slowest in Microsoft Project 2007. Microsoft Project 2010 is an improvement over 2007, but still is substantially slower than Microsoft Project 2003. However, Project 2010 offers many new features over Project 2003, and Project 2003 can't support @RISK 7.x. If you have large projects in which simulation run time is an issue, use the fastest possible hardware configuration.

How do Excel and Project 2013 and 2016 compare to 2010? Benchmarking Windows programs is problematic, because there are so many variables, not only different hardware but different Windows configurations, different programs running in background, and so forth — not to mention different @RISK models. We ran tests with 10,000 iterations of our Parameter Entry Table example from Help » Example Spreadsheets. We used @RISK 7.5.2 in 32-bit Excel and Project 2010, 2013, and 2016, on 64-bit Windows 8, with a 2.8 GHz i7 chip and 8 GB of RAM. We offer our results as anecdotal evidence; they may or may not apply to your system, or your model. And obviously the Parameter Entry Table example is a small one, only eight tasks, so any real project is going to take significantly longer to run.

With those caveats, here is what we found in that example with that system:

Average Times in Seconds
Excel and Project versions2010
Standard Engine  255 s 199 s
Accelerated Engine  34 s 56 s
Multiple runs of one Excel/Project version showed little variation. Differences
between Excel/Project 2013 and Excel/Project 2016 were not significant.

The accelerated engine is available when @RISK distributions and outputs are in just a few commonly used fields of Project; the standard engine allows distributions and outputs in any Project field.

How does our test system compare to your system? Almost everyone has 64-bit Windows. There's more of a split between 32-bit and 64-bit Office, but the majority have 32-bit Office. Switching to 64-bit Office will not increase simulation speed for most @RISK models.

See also: For Faster Simulations

Last edited: 2018-03-05

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