The Economic Importance of Business Software Systems Functional Size Measurement

Abstract

Execution of Business Software Systems (BSS) Development and Enhancement Projects (D&EP) encounters many problems, leading to the high scale of their failure, which then is reflected in considerable financial losses. One of the fundamental causes of such projects’ low effectiveness are improperly derived estimates for their costs and time. In their case, the budget and time frame are determined by the effort being spent on activities needed to deliver product that would be meeting client’s requirements. Meanwhile, objective and reliable effort estimation still appears to be a great challenge, what in the author’s opinion is caused by effort estimation based on resources, while such planning activity should base on the required software product size, which determines work effort. Estimation of BSS size requires using of the suitable software size measure, which has been sought for several decades now. What’s more, it is worth using the capabilities offered by such measure for the BSS D&EP assessment from the perspective being critical to a client, that is from functional perspective. Thus this paper analyses capabilities, being significant from the economic point of view, of taking advantage of suitable approach to the BSS size measurement, with particular consideration given to the two most popular functional size measurement methods normalized by ISO/IEC, namely International Function Point Users Group (IFPUG) method and Common Software Measurement International Consortium (COSMIC) method. This should contribute to the better understanding of the importance of this issue, still being underestimated by business managers – as in the subject literature this issue is usually considered from the technical point of view. Meanwhile, suitable BSS size measurement should constitute the basis for rational activities and business decisions not only for providers, but also for clients needs.