Evolution through architectural reconciliation

One of the possible scenarios in a system evolution cycle, is to translate an emergent set of new requirements into software architecture design and subsequently to update the system implementation. In this paper, we argue that this form of forward engineering, even though addresses the new system requirements, tends to overlook the implementation constraints. An architect must also reverse-engineer the system, in order to make these constraints explicit. Thus, we propose an approach where we reconcile two architectural models, one that is forward-engineered from the requirements and another that is reverse-engineered from the implementation. The final reconciled model is optimally adapted to the emergent set of requirements and to the actual system implementation. The contribution of this paper is twofold: the application of architectural reconciliation in the context of software evolution and an approach to formalize both the specification and trans- formation of the architectural models. The architectural modeling is based upon the UML 2.0 standard, while the formalization approach is based on set theory and first-order logic.