Abstract: To reduce a crisis, heterogeneous actors must coordinate their actions and exchange information. The ISyCri project aims at facilitating this collaboration by providing a Mediation Information System (MIS), which change the set of partners into a system of systems. The design of this MIS is based on the characterization of the crisis and services of actors. The first step of MIS design consists in deducing a collaborative process involving partners of the crisis reduction (from the characterization of the crisis and services of actors). This step is based on a metamodel, which allows to build models (consistent with each other) and ontologies. The inference of the collaborative process is not a trivial issue: The deducing approach uses ontologies and models transformation to organize services according to characteristics of the crisis. This paper discusses this global approach and an illustrative case of study.