Functional Size and Information Theory-Based Functional Complexity Measures: Exploratory study of related concepts using COSMIC-FFP measurement method as a case study

Abstract

This paper presents an exploratory study of related concepts across information theory-based measures and functional size measures. Information theory-based software measurement has been used in the design of an entropy-based measure of functional complexity in terms of an amount of information based on some abstraction of the interactions among software components. As a functional size measurement method, COSMIC-FFP, adopted in 2003 as the ISO/IEC 19761 standard, measures software functionality in terms of the data movements across and within the software boundary. In this paper, we explore some of the links between the two types of measures, and, in particular, the similarities (and differences) between their generic model of software functionality, their detailed model components taken into account in their respective measurement processes and, finally, their measurement function. Some further investigation avenues are also identified for extending the use of functional size measures for reliability estimation purposes and for scenario-based black-box testing