Abstract : Choreography description languages aim at specifying from a global point of view interactions among a set of services involved in a new system. From this specication, local implementations or peers can be automatically generated. Generation of peers that precisely implement the choreography specication is not always possible: this problem is known as realizability. When peers corresponding to this specication are being executed we may want to modify the choreography specication and recongure dynamically the system. This is the case for instance if we add or remove interactions due to the addition of functionalities to the system at hand or the loss of a service. In this article, we present our solutions to check if a choreography is realizable and if a specic reconguration can be applied or not.