A method for processing a sequence of fault messages occurring in a device including many systems, makes it possible to discriminate between fault messages most likely originating from a real system fault and fault messages without any real fault in the associated system (no fault found), characterized in that the method combines: an “air-side” method (100) executed in real time for acquiring fault message data defining sequences stored in a fault database and for immediate diagnosis assistance using a diagnostics tool, and a “ground-side” method (200) for the subsequent analysis of fault sequence data and for improving the diagnostics tool.