Visualizing software release histories: the use of color and third dimension

The data regarding the components of a software system consists of a large amount of information such as version history, number of lines, defect density, and complexity measures. The ability to quickly grasp a comprehensive view of the evolution and dependencies of such information is the key to making informed decisions about future developments of the system. Managers usually make such decision based only on expert judgement. For help in making such decisions, we can turn to the evolution history of large software systems, which contain a wealth of hidden information. Traditionally, this information is passed on through anecdotes without any supporting analytical data. This paper reports on our attempts to make such information more concrete through information visualization techniques. We present a three-dimensional visual representation for examining a system's software release history. The structure of the system is displayed by 2D or 3D graphs. The historical information is displayed by using time as the third dimension. Colors are used for displaying module properties and their historical changes in the system. A supporting software tool enables not only visualization but also navigation in the 3D space to change the viewpoint, to browse system information, to find interesting patterns and to discover previously unknown relationships among system components.