Software Evolution and Human Resources: Knowledge Gap left by Developers due to Turnover

From a traditional point of view, software evolution is a field of research which is commonly interested in how the source code evolves. However, developing software is a task full of intellectual effort and people behind a software are key factors for its evolution. Thus, human resources are also interesting in the field of software evolution or maintenance since the wrong people in the wrong place may provoke chaos. Generally speaking, not everybody has the right to modify the source code, but we may find situations where there is a turnover of developers and senior developers leave a project. In this case, a new developer will take control of the old source code. From an intuitive point of view, this produces a decrease in the level of quality for maintenance activities.
Fixing a bug will take more time to a junior developer than to the senior one. Hence, situations such as: discovering areas with no activity during a long time, detecting that the current developer team has a low knowledge of the source code or studying the huge ”knowledge gap” left by a developer when she left; are essential for the leaders of a libre software community. This thesis aims to clarify those aforementioned situations from an empirical point of view looking for risky situations due to developer turnover.