The present invention relates to a method and device for validating a data flow system represented by a data flow graph, comprising: —an acquisition module (9) configured to acquire data related to first and second common parts of the data flow graph, and—a supervision module (11) configured to incrementally verify the coherence of the data flow system by verifying the local coherence of a common unidirectional connection connecting the first common part of the data flow graph to the second common part of the data flow graph at each increment.