Components, Contracts, and Connectors for the Uni ed Modelling Language UML

Abstract. The lack of a component concept for the UML is widely ac-knowledged. Contracts between components can be the starting point for introducing components and component interconnections. Contracts between service providers and service users are formulated based on ab-stractions of action and operation behaviour using the pre- and postcon-dition technique. A valid contract allows to establish an interconnection- a connector- between the provider and the user. The contract concept supports the re-use of components by providing means to establish and modify component interconnections. A flexible contract concept shall be based on a renement relation for operations and classes, derived from operation abstractions. Abstract behaviour, expressed by pre- and post-conditions, and renement are the key elements in the denition of a formal and flexible component and component interconnection approach.