Productivity, Turnover, and Team Stability of Agile Teams in Open-Source Software Projects

Productivity in software development has been studied for a long time and is still a topic of interest. Many factors, ranging from team size to music listened by developers, have been studied regarding their effect on productivity. Surprisingly, little is known about how the dynamics of open-source projects that use agile practices are related to the productivity of the developer teams. Our study aims to close this gap by analyzing the productivity of open-source projects using measures that are popular in the context of agile software development. To do this, we study data from seven open-source projects and calculated both the individual velocity of developers and focus factor of teams per iteration. First, we applied statistical process control to identify iterations with out-of-control velocity and focus factor values. Then, we studied these iterations regarding four context factors that partly characterize the dynamics of open-source projects, i.e., iteration length, turnover of developers who left, turnover of new developers, and team stability index. Our results suggest that high team stability and low turnover are strongly associated with iterations showing high velocity.