Software evolution: analysis and visualization

Gaining higher level evolutionary information about large software systems is a key challenge in dealing with increasing complexity and decreasing software quality. Software repositories such as modifications, changes, or release information are rich sources for distinctive kinds of analyses: They reflect the reasons and effects of particular changes made to the software system over a certain period of time. If we can analyze these repositories in an effective way, we get a clearer picture of the status of the software. Software repositories can be analyzed to provide information about the problems concerning a particular feature or a set of features. Hidden dependencies of structurally unrelated but over time logically coupled files exhibit a high potential to illustrate software evolution and possible architectural deterioration. In this tutorial, we describe the investigation of software evolution by taking a step towards reflecting the analysis results against software quality attributes. Different kinds of analyses (from architecture to code) and their interpretation will be presented and discussed in relation to quality attributes. This will show our vision of where such evolution investigations can lead and how they can support development. For that, the tutorial will touch issues such as meta-models for evolution data, data analysis and history mining, software quality attributes, as well as visualization of analysis results.