Using Architectural Properties to Model and Measure System-Wide Graceful Degradation

System-wide graceful degradation may be a viable approach to improving dependability in computer systems. In order to evaluate and improve system-wide graceful degradation we present initial work on a component-based model that will explicitly define graceful degradation as a system property, and measure how well a system gracefully degrades in the presence of multiple combinations of component failures. The system’s software architecture plays a major role in this model, because the interface and component specifications embody the architecture’s abstraction principle. We use the architecture to group components into subsystems that enable reasoning about overall system utility. We apply this model to an example distributed embedded control system and report on initial results.