Other business measures, such as the productivity of the development process and the cost per unit to support the software, can also be readily derived.
The function point measure itself is derived in a number of stages. Using a standardized set of basic criteria, each of the business functions is a numeric index according to its type and complexity. These indices are totaled to give an initial measure of size which is then normalized by incorporating a number of factors relating to the software as a whole. The end result is a single number called the Function Point index which measures the size and complexity of the software product.
VisualFSM IFPUG Demo
Click on picture to watch the video