A device (D) is intended for optimizing composite applications comprising at least two orchestrated activities participating to at least one process. This device (D) comprises i) an analyzing means (AM) arranged for determining orchestrated activities contained into a composite application to be optimized and dependencies between these activities, and ii) an optimizing means (OM) arranged for determining a new orchestration between the determined activities which allows the composite application to execute requests of users in a minimal time, according to the determined dependencies and to predefined rules, and for outputting an optimized composite application based on the new orchestration.