On the applicability of COSMIC-FFP for measuring software throughout its life cycle

Software measurement plays a key role in software engineering and, to improve its performance, an organisation needs to measure software at each stage of the development life cycle. Recently, the COSMIC-FFP measurement method has been developed to improve the measurement of the functional size of a large array of software types. By quantifying software’s functional user requirements, the method makes it possible to measure software from the user’s viewpoint. The COSMIC-FFP measurement method has been designed based on a software functional model that can represent the functional user requirements at many levels of functional abstraction, such as software layers, functional processes and data movement sub-processes. Developers in general, however, need to know the size of the software early in the development process to support the estimation and project planning process. While the measurement rules of the COSMIIC-FFP method have been designed to be applied when the details of the software functions are known, the method has the required flexibility to capture an estimate of the functional size of software early in the life cycle and to offer added value to the software engineers preparing the development plans. This paper investigates the applicability of COSMIC-FFP for measuring the size of software at early stages of the development life cycle.