The Problem with Function Points

he concept of function points goes a long way toward addressing the genuine need for frontend measures of product size. My concern is that specific types of function points—such as Albrecht’s version,1 which is popular in the US, and Symons Mark II version,2 which is popular in the UK—are not the straightforward, simple measures some people imagine. Function points have fundamental flaws in their construction that prevent them from being valid measures.3 This means there is a danger they will behave in unexpected ways, for example asserting that one program is larger than another when it is not. In most cases, if function points are used with caution within a specific organization, you will probably have few problems. But if you want to use them for cross-company benchmarking, as the basis for development or support contracts between different companies, or to develop generic estimation models, there is a non-negligible risk that you will encounter problems.