The research conducted within the project DIRAC focus on the recent issue of tolerance to faults/failures in dynamic systems with associated fault diagnosis. The main contribution of this project consists in the development of a general diagnosis/reconfiguration methodology dedicated to complex systems. The design of such approach from "diagnosis model" until the reconfiguration phase of the system requires the "diagnosability", observability and "reconfigurability" studies. In this context, our research focuses on the analysis of structural properties both for the design and the one-line tuning. Moreover, the synthesis of novel strategies for the control law reconfiguration and/or the sub-system restructuration will be an other target in this project. In order to guarantee the quality of the product and to ensure integrity of the system as well as human safety, tolerance strategy will be developed according to the recovery/trajectory control reference input, the fault diagnosis performances, the reliability of the system….