Mining the history of synchronous changes to refine code ownership

When software repositories are mined, two distinct sources of information are usually explored: the history log and snapshots of the system. Results of analyses derived from these two sources are biased by the frequency with which developers commit their changes. We argue that the usage of mainstream SCM systems influences the way that developers work. For example, since it is tedious to resolve conflicts due to parallel commits, developers tend to minimize conflicts by not contemporarily modifying the same file. This however defeats one of the purposes of such systems. We mine repositories created by our Syde tool, which records every change by every developer in multi-developer projects. This new source of information can augment the accuracy of analyses and breaks new ground in terms of how such information can assist developers. In this paper we illustrate how the information we mine can help to provide a refined notion of code ownership. As a case study, we analyze the developers' activities of the development of a commercial system.