How can I change the unit for Total system size in the Balanced Risk and other solution wizards? Currently it is set to IU, but we use Function Points.

Solution wizards that require a size estimate assumption use the Sizing By History technique to obtain an initial "ballpark" estimate based on the statistical size ranges, or t-shirt sizes, in your project's associated trend group(s).  This technique uses the Function Unit and Gearing Factor in the Project Environment settings.  Most of the templates installed with SLIM-Suite have the Function Unit set to the Base Size Unit, either IU or SLOC.  

To change the Function Unit to Stories, Features, Function Points, or other size unit, select Tools | Customize Project Environment from the menu. On the Project Description Tab, there is a Function Unit list box.  Select Function Points or other unit, then enter an appropriate Gearing Factor to represent the average number of Base Size Units (elementary programming steps) contained in your selected  Function Unit (ex.: a gearing factor of 50 represents 50 Base Size Units per Function Point).  

If you need help determining an appropriate gearing factor, visit the Function Point Gearing Factors page on the QSM web site, download our Gearing Factors whitepaper, or contact QSM for assistance.