Coordination architecture for evolvable event-based systems

Event-based and publish/subscribe systems provide levels of flexibility and agility that bring us much closer to what is required for operating in business environments that are "time critical". It is essential that the evolution of systems be driven in terms of the business concepts that underlie the requirements for change or determine the dynamics of service procurement, and not the lower level design mechanisms available in the middleware and in terms of which the system is designed. present an overview of a set of modelling techniques that address these issues. Our proposal is based on a layered abstract architecture that enforces a strict separation between two levels of modelling, the rationale for which is the realization that, when addressing the dynamics of system evolution, it is possible to distinguish two different rates of change and address them separately.