A Rule-Based Approach to Framework Evolution

Framework development is very expensive, not only because of the intrinsic difficulty related to capturing the domain knowledge, but also because of the lack of appropriate methods and techniques to support the evolution of the framework architecture. In this context, we introduce the concept of extension rules. Extension rules allow the addition of new features into the framework design, making sure the consistency with the applications previously instantiated. We propose the use of extension rules in combination with the refactoring approach to support framework evolution. In addition, we propose a methodology to prove the correctness of evolution processes. The approach is illustrated through Avestruz, a framework for web searching.