Abstract: A device and a method for the analysis and troubleshooting of a system, based on the use of a model of the system, with application in particular in the area of industrial installations controlled by automatic control systems of the programmed or wired logic type. The method includes a stage for initialisation of the model, and a stage for the creation of a list of discordant variables whose value in the system differs from that predicted by the model. For each of the variables belonging to a discordance list, an initial list of suspect variables, suspected of having generated the discordant value, is created, and then a restricted list of suspect variables is obtained by filtration of the initial list.