Rearchitecturing Legacy Systems— Concepts & Case Study

Legacy systems, no matter which architectural style they rely on, contain numerous pieces of source code with very similar functionality. We see these system aspects as a good starting point for rearchitecturing legacy systems. The goal is the evolution of the legacy system architecture towards a product line architecture which incorporates the originally replicated system aspects as reusable, ideally self-configuring components. This paper presents the concepts which we regard as necessary and/or useful for such an evolution: Framelets form small architectural building blocks that can be easily understood, modified and combined. Reflection together with a high-level definition of semantic aspects allow the construction of partially self-configuring components. A case study corroborates that this constitutes a viable approach for rearchitecturing legacy systems in practice.