This article introduces you to how the xlCompare Add-in can be used to perform what-if analysis.
You need to do the following steps in order to perform what-if analysis:
With xlCompare you can instantly see effect of your changes. Also you can export results for future analyze or to create a report for your model.
You can compare not only output of your model, but the internal values in the logic also. This is useful when you are debugging your model.
If you need to find out why your model produces unexpected or wrong result, we would like to suggest you to try the Dependency Auditor. This powerful and handy add-in allows you to do drill-down tracing in your workbook. You can see analyze you your model works in a few seconds.
Dependency Auditor finds "hidden" dependencies in your model produced by OFFSET and INDIRECT functions, which you can't see using usual Tracing tool in Microsoft Excel.
In the acticle Analyze formula values in the Excel Workbooks you can find more information about this tool.
Example of the Dependency Auditor tracing results: