Abstract
While there are many software metrics measuring the architecture of a system and its quality, few are able to assess architectural change qualitatively. Given the sheer size and complexity of current software systems, modifying the architecture of a system can have severe, unintended consequences. We present a method to measure architectural change by way of structural distance and show its strong relationship to defect incidence. We show the validity and potential of the approach in an exploratory analysis of the history and evolution of the Spring Framework. Using other, public datasets, we corroborate the results of our analysis