Interconnecting objects via contracts

Abstract

The evolution of today’s markets and the high volatility of business requirements put an increasing emphasis on the flexibility of systems, i.e. on the ability for systems to accommodate the changes required by new or different organisational needs with a minimum impact on the implemented services. In this paper, we put forward an extension of UML with a semantic primitive — contract — for representing explicitly the rules that determine the way object interaction needs to be coordinated to satisfy business requirements, as well as the mechanisms that make it possible to reflect changes of the business requirements without having to modify the basic objects that compose the system. Contracts are proposed as extended forms of association classes whose semantics rely on principles that have been used in Software Architectures and Distributed System Design for supporting dynamic reconfiguration.