Functional Size Measurement Methods - COSMIC - FFP : Design and Field Trials

Measuring the functional size of software was proposed by Albrecht, more than 20 years ago, as a solution to the limitations of lines of code (SLOC) when quantifying the output of the software engineering process. While this approach has been, and still is, successful when applied to MIS type of software, it has not enjoyed the same success for measuring the size of non MIS software, as demonstrated in publications from a number of authors in the past 15 years. Three types of approach have been proposed in the literature to apply Albrecht’s concepts to non MIS types of software. Although some of these approaches offered interesting insights, none has gained sufficiently wide usage to be recognized as a de facto standard. Building on the strengths of previous work in this field, the Common Software Measurement International Consortium (COSMIC) proposed a set of principles in 1998 onto which a new generation of functional size measurement methods could be built. The COSMIC group then published version 2.0 of COSMIC-FFP, in 1999, an example of a functional size measurement method built on those principles. Key concepts of its design and of the structure of its measurement process are presented.