ESA_PetriNet: a Tool for Extracting Scenarios in Computer Controlled Systems. This paper deals with the dynamic reliability of a computer-controlled system by means of deriving critical scenarios from its Petri net model. These scenarios characterize how the system leaves the normal operating to go to the feared state by determining the sequences of actions (events) and state changes leading to dangerous situation. We present a method (algorithm) that takes into account the continuous dynamic of the system by a temporal abstraction, which makes it possible to determine more precisely the exact conditions of the occurrence of the feared event. The originality is that the order of occurrence of the events is taken into account, and impossible scenarios with respect to the continuous dynamic of the system are eliminated. The automation of all the steps of this method has led to the development of ESA_PetriNet tool (Extraction Scenarios & Analyzer by Petri Net model) and was applied on real industrial systems.