An aspect-oriented approach for improving architecture design efficiency

Our experience shows that the discipline of software architectures must face the challenge of scaling with the ever increasing size and complexity of requirements imposed on system development in order to be able to deliver high-quality products on time. That is, software architecture methods need to provide practical support for efficiently and effectively predicting, controlling, and evolving required product properties throughout the entire lifecycle of software-intensive products. Traditionally, software architecture utilizes the principle of separation of concerns to cope with the challenge of scalability of solutions to complex problems. For instance, by encapsulating functionality into self-contained units and applying information hiding, large and complex systems are decomposed into modules that can be developed and integrated independently. In the context of non-functional concerns, however, separation of concerns does not work as well. Since the focus during decomposition is on the identification of components that aggregate semantically cohesive chunks of functionality, the inter-component dependencies remain side-affected by solutions addressing non-functional concerns. This is particularly true for component interdependencies that specify inter-component communication. The interactions among components become more critical determinants of system properties as components become more complex and heterogeneous. The main solution idea of this thesis is to leverage aspect-oriented concepts at the architectural level in order to provide a means for effectively and efficiently separating communication concerns in the context of architectural design. The primary contribution of this thesis comprises a formalization of architectural models and a method that supports the design process with sophisticated extensions of a commercial architecture design tool. The aspect-oriented architecture model, the design method, and the tool support are fundamental ingredients for efficiently implementing the principle of separation of concerns at the level of architectural interconnection. The proposed solutions are validated by means of a controlled experiment showing that the aspect-oriented separation of communication concerns indeed improves the design efficiency of architectures.