Describing evolving dependable systems using co-operative software architectures

The paper describes an architectural approach that facilitates the modelling and analysis of dependable systems that are built from untrustworthy components whose designs, we assume, cannot be changed. The approach is based on the definition of an architectural style in which connectors are considered as first class entities, which embody the description of collaborative behaviour between components. This style is shown to be particularly suitable for describing system components that have to evolve in order for the system to provide dependable services. The feasibility of the proposed architectural style in dealing with evolving dependable systems is demonstrated in terms of a gas station case study.