A method of assistance for troubleshooting is provided. A purpose is to prioritize identifiers each associated with a piece of equipment the failure of which can be the cause of a fault within an aircraft. The method is based on transmitting to an expert system, a list of identifiers, and receiving, for each identifier, a family of pertinent parameters, with each pertinent parameter being associated with at least one sensor of the aircraft and taking measurements of the pertinent parameters. Knowing these measurements, it is possible to deduce therefrom, for each identifier, a priority corresponding to the probability that the associated equipment is effectively defective. A system for implementing this method is also provided.