Integrating COTS Software Components into Dependable Software Architectures

This paper considers the problem of integrating commercial off-the-shelf (COTS) software components into systems with high dependability requirements. These components, by their very nature, are built to be reused as black boxes that cannot be modified. Instead, the system architect has to rely on techniques external with respect to the component for resolving mismatches of the services required and provided that might arise in the interaction of the component and its environment. An approach is described in this paper to how these techniques should be structured around the COTS component to obtain an idealised fault-tolerant component. The approach employs the layer-based C2 architectural style for structuring mechanisms of error detection and recovery that should be integrated into the software architecture. The feasibility of the proposed approach is presented in the context of a steam boiler system which contains a COTS controller