Analysing change profiles of open source software projects using burst detection

Software evolution refers to the phenomenon of continuous software change and growth after its initial development. A version control system records all information about these changes. Several research studies in the past have studied the historical records of changes of open source software (OSS) projects and found them useful for understanding the software evolution process. However, most of them investigate the distributions of changes types, change size, and change effort in an isolated manner. There is no work, to the best of our knowledge, which takes a combined view of various dimensions of a change. This study examines the change activity in 106 OSS projects from three points of view: change purpose (type), change size, and change effort. The common patterns in change type, change size, and change effort are highlighted using the burst detection technique. The burst detection technique helps in identifying the peaks in the time series and compares them with the peaks of other time series. The results indicate that the change-type activity of OSS projects is significantly related with change effort, and change size for high and moderate-activity clusters. Though for low-activity cluster, this commonality of patterns is not there for all types of changes.