Can We Predict the Generation of Bugs? Software Architecture and Quality in Open-Source Development

We study how software architecture relates to quality. Based on a software architecture representation that accounts for not only the hierarchical arrangement of its subsystems and components but also their dependency structure, we formally define the notion of system cyclicality. System cyclicality is an architectural property that captures the fraction of mutually interdependent components in a system. By examining multiple versions of 20 open-source, java-based applications (126 total) developed by the Apache Foundation, we empirically analyze the relationship between software architecture characteristics and the creation of bugs. Our results suggest that, while controlling for various system characteristics, system cyclicality is a key determinant of bug creation. Interestingly, we found evidence that it is not just the cycles themselves, but how hidden they are, that drive the effects of system cyclicality and bug creation. From an academic viewpoint, this work provides a theoretical and empirical basis for a causal link between the architecture of a complex system and its quality. This has important implications for the management of complex system design and development in fast-paced industries such as software. Our results suggest that managers could benefit from proactively examining the architecture of the system they develop and monitoring its cyclicality as one of their strategies to mitigate the creation of defects. DRAFT – Please, do not quote or distribute without permission 1