Structural evolution of software: a social network perspective

Structural evolution of an object oriented software is studied using a class collaboration network. The emergence of scale-free property in this network from what could be a random network suggests an inherent process of structural optimization. In the past, software evolution was studied using object oriented metrics. But, these metrics limit our understanding of structural evolution because they are object-class centric and do not take into account the complex relations that span across the structure. As an initial attempt, we apply the social network theories to uncover this hard-to-understand yet essential process of structural evolution. We discuss our findings related to the occurrences of complex relations and influential object-classes that resist the optimization. We do so by observing the revisions chosen at different stages of evolution from open-source software projects.