Component usefulness measures for fault tolerance evaluation

Component-based models are very useful for the design of reliable systems. In this paper we focus on properties sensitive to the availability of components (e.g. sensors or actuators). To evaluate the degree of fault tolerance of a given property, we propose usefulness measures of components based on the lattice of system configurations. Being quite general, the approach needs no assumption on the system. A sensor network design example for the output connection property illustrates the practical use of the proposed tools.