Adapting Function Points to contemporary software systems: A review of proposals

Software size is an important measurement for the objective evaluation of software engineering characteristics such as productivity and quality. Currently, Function Point Analysis (FPA) is emerging as a credible technique that allows software professionals to measure the external functional size of software systems. While FPA has gained significant momentum, it does have its critics. Some criticisms, such as inadequately addressing internal complexity, would seem to be justified for certain application domains. Since the inception of function points by Allan Albrecht in 1979 there have been a number of extensions proposed. This paper reviews the ‘current state of play’ by reviewing the function point model and a number of extensions that specifically address the measurement of contemporary software systems. The different models are analysed in terms of their computational characteristics, measurement scope, useability and acceptability. The results indicate that FPA does not address all the needs of contemporary software measurement. However, FPA can provide useful results when used in an appropriate context. The results also indicate that while significant progress has been made by a number of extensions, there is not enough attention made to measurement theory, verification and validation of new and evolving models.