Exploring Complexity in Open Source Software: Evolutionary Patterns, Antecedents, and Outcomes

Software complexity is important to researchers and managers, yet much is unknown about how complexity evolves over the life of a software application and whether different dimensions of software complexity may exhibit similar or different evolutionary patterns. Using cross-sectional and longitudinal data on a sample of 108 open source projects, this research investigated how the complexity of open source project releases varied throughout the life of the project. Functional data analysis was applied to the release histories of the projects and recurring evolutionary patterns were derived. There were projects that saw little evolution, according to their measures of size and structural complexity. However, projects that displayed some evolution often differed on the pattern of evolution depending on whether size or structural complexity was examined. Factors that contribute to and result from the patterns of complexity were evaluated, and implications for research and practice are presented.