This article deals with the impact evaluation of interoperability decision variables on performance indicators of business processes. The case of partner companies is studied to show the interest of an Interoperability Service Utility (ISU) on business processes in a peer to peer (P2P) collaboration. Information described in the format and the ontology of a broadcasting entity is transformed by ISU into information with the format and the ontology of the receiving entity depending on the available resources of interoperation. These resources can be human operators with defined skill level or software modules of transformation in predefined languages. A design methodology of a global simulation model for estimating the impact of interoperability decision variables on performance indicators of business processes is proposed. Its implementation in an industrial case of collaboration shows its efficiency and its interest to motivate an investment in the technologies of enterprise interoperability
