An Investigation on the Relative Cost of Function Point Analysis Phases

Function Point Analysis (FPA) is widely used, especially to quantify the size of applications in the early stages of development, when effort estimates are needed. However, the measurement process is often too long or too expensive, or it requires more knowledge than available when development effort estimates are due. To overcome these problems, early size estimation methods have been proposed, to get approximate estimates of Function Point (FP) measures. In general, early estimation methods (EEM's) adopt measurement processes that are simplified with respect to the standard process, in that one or more phases are skipped. EEM's are considered effective; however there is little evidence of the actual savings that they can guarantee. To this end, it is necessary to know the relative cost of each phase of the standard FP measurement process. This paper presents the results of a survey concerning the relative cost of the phases of the standard FP measurement process. It will be possible to use data provided in the paper to assess the expected savings that can be achieved by performing an early estimation of FP size, instead of properly measuring it.