The general objective of the PERSI team is to guarantee the operational availability and sustainability of industrial system equipment. This integrated problem requires in a first phase to detect and isolate the faults before failure (progressive faults and cataleptic faults) then in a second step, to predict (anticipate failures) and finally, in a third step, to estimate the remaining useful life or manage operation in degraded mode. Based on literature review, the three phases are treated mainly independently., the three phases are treated independently. The general theme that characterizes the PERSI team consists of considering the different aspects of sustainable systems design in a simultaneous and consistent way, namely modeling (functional and behavioral), diagnosis, prognosis of energy systems together with their computational implementation. The tools used are based on graphical formalisms and multiphysics (Event Driven Hybrid Bond Graph, functional graphs) Artificial Intelligence and formal modeling tools. The main application domain concerns renewable energies (green hydrogen, multisource systems, fuel cells, etc.), transport and production systems.