This paper presents a solution to the Flowgraphs case study for the Transformation Tool Contest 2013 (TTC 2013). Starting from Java source code, we execute a chain of model transformations to derive a simplifi ed model of the program, its control flow graph and its data flow graph. Finally we develop a model transformation that validates the program flow by comparing it with a set of flow specifi cations written in a domain speci c language. The proposed solution has been implemented using ATL.