Identifying Architectural Change Patterns in Object-Oriented Systems

As an object-oriented system evolves, its architecture tends to drift away from the original design. Knowledge of how the system has changed at coarse-grained levels is key to understanding the de facto architecture, as it helps to identify potential architectural decay and can provide guidance for further maintenance activities. However, current studies of object-oriented software changes are mostly targeted at the class or method level. In this paper, we propose a new approach to modeling object-oriented software changes at coarse-grained levels. We take snapshots of an object-oriented system, represent each version of the system as a hybrid model, and detect software changes at coarse-grained level by comparing two hybrid models. Based on this approach, we further identify a collection of change patterns, which help interpret how system changes at the architecture level. Finally, we present an exploratory case study to show how our approach can help maintainers capture and better comprehend architectural evolution of object-oriented software systems.