Mobile Components as Topological Action Systems

Component-based software engineering means assembling software systems from existing, service-providing components. The increased flexibility and reliability of the component-based systems are among the main benefits of this method. However, for ensuring the correctness of their services, the components themselves should be correctly developed. The topological action systems approach provides a formal model for world-wide software resources. This framework is based on the refinement calculus, a specification language with well-defined semantics and logic for reasoning. Topological action systems can be correctly developed using refinement techniques, but they lack some of the flexibility features required by world-wide networks. Hence, both the component-based development and the topological action systems model of specification can benefit from them being integrated. We present the principles of this integration, argue for mobility being a natural component property and further study the refinement of mobile components.