International audienceThe risk analysis of a system is a multidisciplinary process in constant evolution. Indeed, if a few years ago, analyses were limited at the technical level, it is today necessary to consider the system in a global way, by including Human beings and Organisations. But this involves an increasing complexity of the studied system, because of the widening of its limits and the diversity of considered disciplines. This article proposes a method to structure the knowledge in a decisionmaking model