Using COSMIC-FFP to Quantify Functional Reuse in Software Development

One of the means organisations use to adequately measure the performance of their software engineering process, is to try to identify how much reuse has actually occurred. In this paper, the COSMIC-FFP (COSMIC-Full Function Points) measurement method is proposed as a method for quantifying reuse from a functional perspective rather than from a technical perspective. The COSMIC-FFP method has been developed to improve the measurement of the functional size of various software types: real-time, technical, system and MIS software. By using functional user requirements as input, the method makes it possible to measure the size of software from the user’s viewpoint. When other functional perspectives are taken into account in the measurement process, the other results may be used as complementary information related to the measured software. The value of this new information includes the ability to quantify reuse from a functional perspective, and as such it would be worth considering taking it into account in the software productivity model. Some practical results on industrial software are presented, along with the concepts involved.