Home → Troubleshooting → @RISK for Excel: Other Issues → Excel Files with @RISK Grow Too Large

8.4. Excel Files with @RISK Grow Too Large

Applies to: @RISK 5.x–7.x

My Excel workbook containing my @RISK model takes a long time to open, and Excel seems to be unstable because of the large file size. My model was not nearly this large originally, but grew much larger when I ran a simulation and then saved the Excel workbook. What can I do?

When you run a simulation, @RISK can save simulation results in the Excel workbook or in a separate .RSK5 file, or neither. It sounds like you have @RISK set to save results in the Excel workbook, or you had @RISK set that way in the past. To clear those results and reduce the size of this workbook, follow this procedure:

(optional) To export the current simulation results, click Utilities » Save Simulation File.
In @RISK's Utilities menu, select Clear @RISK Data. In that dialog, select "Simulation Results" and clear any marks that appear for the other options. Click OK and answer the confirming prompt. Save your workbook.

How can I prevent my workbook from growing again with future simulations?

Either save results in an external .RSK5 file, or don't save them at all. (If you want to save selected results, use the @RISK Library, which is available in the Professional and Industrial Editions of @RISK.)

Here's how to register your preference with @RISK:

In @RISK's Utilities menu, open Application Settings.
In the General group, in the left column, locate "Save Results". If that is set to "Automatically Save in Workbook", change it to "Prompt on Save", "Save to External File", or "Never Save Results". Click OK.

With "Save to External File" in Application Settings:
Whenever you save your workbook after running a simulation, @RISK opens a Save @RISK Results dialog showing the default external file name and the size of the results. Click Yes to save results to that file, click No to skip saving results, or click the Options button to choose a different file name and location. (In @RISK 5.x/6.x, there's a Save Options icon rather than a button.)

With "Prompt on Save" in Application Settings:
Whenever you save your workbook after running a simulation, @RISK opens a Save @RISK Results dialog telling you how large the results are. However, the default in this case is to save results in the same workbook. Click Yes to accept this choice, click No to skip saving results, or click the Options button to save results to an external file. (In @RISK 5.x/6.x, there's a Save Options icon rather than a button.)

With "Prompt on Save", if you run additional simulations in this session, the default save location will remain as the .RSK5 file. But if you close @RISK and restart it, the default save location will change to "workbook". When answering the Save @RISK Results dialog, always check the save location and, if necessary, click the Save Options icon to select the external .RSK5 file.

With "Never Save Results" in Application Settings:
Beginning with @RISK 7.5, you can save results to an external file anytime after running a simulation. Just click Utilities » Save Simulation File. You'll be prompted to choose a folder and a file name. (Actually, you can do this no matter which Application Settings you have. But it's particularly useful when you chose "Never Save Results".)

How do I get access to the saved results when I reopen my Excel file in a later session?

First open your model—a results file won't work correctly unless the model is also open. @RISK should pop up a dialog box:

Open Saved @RISK Results from file location?

If the results file was moved or renamed, @RISK won't be able to find it and won't display that dialog. Click Utilities » Open Simulation File... to select the RSK5 file that contains your results.

If your simulation results file is very large, and you have 32-bit Excel, @RISK may not be able to open it. Try closing other programs, and if that's not enough you may need to switch to 64-bit Excel.

Last edited: 2019-02-11

This page was: Helpful | Not Helpful