Design of a Functional Size Measurement for Real-time Software

A requirement for software productivity analysis and estimation is the ability to measure the size of a software product from the user’s viewpoint, that is, from a functional perspective rather than from a technical perspective. One example of such a measurement method is Function Point Analysis (FPA). FPA is now widely used in the Management Information Systems (MIS) domain, where it has become a “de facto” standard. However, FPA has not achieved the same degree of acceptance in other domains of software engineering, such as real-time software. The general opinion is that when FPA is applied to such software the results do not constitute an adequate size measurement of this type of software. This paper reports on a research project carried out to adapt FPA to the specific functional characteristics of real-time software. The proposed extension, called Full Function Points (FFP), is described and the results of field-testing are discussed. This research was conducted using an adaptation of Basili’s framework for empirical research in software engineering and it is described accordingly.