Home → Techniques and Tips → @RISK Simulation: Numerical Results → More Than 50,000 Iterations to Converge
6.2. More Than 50,000 Iterations to Converge
Applies to: @RISK 6.1.1 and newer
I have set up convergence, with iterations set to Auto, but @RISK stops at 50,000 iterations although not all of my outputs have converged.
@RISK 8.x
The application comes with an interface where the user can choose the maximum number of iterations for Auto Stop. This option is enabled when the user selects the "Auto" setting in the number of iterations field. When the Simulation Settings User Interface is open, a new field labeled "Maximum of" will let the user define the maximum number of iterations.
Details can be found in the Online Help
@RISK 6.1.1 and 7.x
By default, @RISK stops at 50,000 iterations rather than keep iterating indefinitely. However, it is true that some models will eventually converge, but at some point after 50,000 iterations. You could set a higher number of iterations explicitly instead of Auto, but then you lose convergence monitoring.
Beginning with @RISK 6.1.1, you can change that 50,000-iteration limit for convergence monitoring. Create a workbook-level name RiskMaxItersForAutoStop with a value such as =100000. (The leading = sign is required.) With iterations set to Auto, @RISK will stop when outputs converge, or when the RiskMaxItersForAutoStop number of iterations is reached, whichever happens first.
To create a workbook-level name in Excel 2007, Excel 2010, and Excel 2013, click Formulas » Name Manager » New. Enter the name RiskMaxItersForAutoStop. In the Refers-to box, enter your desired maximum number of iterations for convergence monitoring, preceded by the = sign. Click OK and then Close.
To create a workbook-level name in Excel 2003, click Insert » Name » Define. In the box at the top, enter the name RiskMaxItersForAutoStop. In the Refers-to box, enter your desired maximum number of iterations for convergence monitoring, preceded by the = sign. Click Add and then OK.
During simulation, the progress window at the lower left of your screen shows a percent complete. If iterations is Auto, @RISK doesn't know how many iterations will be needed until convergence has occurred, so it computes the percent complete on a basis of 100% = 50,000 iterations. If you have set RiskMaxItersForAutoStop to a larger number, and more than 50,000 iterations are needed, the percent complete will go above 100%.
Last edited: 2020-06-01