In order to use a sizing unit other than SLOC in the SLIM tools, you must assign a gearing factor. For function points, gearing factors are discussed here. In this article, QSM's Andy Berner addresses ways of choosing a gearing factor for story points.
Part of QSM's Agile Round Table article series, the fourth article focuses on determining size in a consistent enough manner across multiple products, projects, and agile teams so that you have good historical data on which to base an estimate. It also shows how to apply these techniques with the SLIM Suite of products.
In this article for IFPUG's Metric Views, Carol Dekkers and Joe Madden suggest a new way to repurpose function points to achieve software project estimating successes today.
This article discusses how the SLIM agile bidding solution will save you time and money and allow you to make more informed bidding decisions.
How can I quantitatively evaluate potential suppliers and determine whether or not a potential supplier is likely to perform as promised?