Components, Contracts, and Connectors for the Unified Modelling Language UML

Abstract

Abstract. The lack of a component concept for the UML is widely acknowledged. Contracts between components can be the starting point for introducing components and component i n terconnections. Contracts between service providers and service users are formulated based on abstractions of action and operation behaviour using the pre-and postcondition 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 i n terconnections. A exible contract concept shall be based on a re nement relation for operations and classes, derived from operation abstractions. Abstract behaviour, expressed by pre-and postconditions, and re nement are the key elements in the de nition of a formal and exible component and component i n terconnection approach.