Fault tolerance evaluation for component based models

International audience; Component based models are very useful for the design of reliable systems since they allow for an easy introduction of components faults. As basic components, sensors and actuators have motivated a huge amount of work. Evaluation issues are important during the system design, for example the usefulness of a component allows to decide its maintenance policy or duplication for redundancy. Few works have dealt with evaluation issues in the control community. In this presentation we develop a comprehensive lattice representation of component based systems models aimed at providing tools for fault tolerance evaluation. This general representation needs no specific asumption on the system. This simple framework allows to propose interesting usefulness measures of components. In this talk we describe the underlying ideas of this new representation and illustrate the results with very simple academic examples