The Diagnosis Approach used in SACHEM

This paper proposes the approach used to design the diagnostic function of the SACHEM system, based on behavioral knowledge of the controlled system and using the DEVS formalism (Discrete EVent Specification) for building executable models. Our methodology is supported with an environment including: • The ELP (Expert Language Process) language to acquire and represent expert knowledge; • The DEVS formalism to make operational conceptual expert models; • Algorithms for exploiting DEVS models used for both prediction and diagnosis of dynamic systems.