A safety barriers-based approach for the risk analysis of socio-technical systems

Usually, an efficient interaction between different resources of an industrial system (technical, human and organizational) leads to an efficient operation of this system. If this interaction is too weak due to missing or failing resources, the system can evolve to inoperative or risky situations, which can be hazardous for critical systems (as nuclear power plants and chemical processes). Thus methodologies are needed to support risk analysis by integrating together these system dimensions. Nevertheless few existing methodologies are able to perform this task and are mainly dedicated to partial or specific application domains. To face this gap, the paper presents a new methodology based on a system knowledge unification and its structuring in order to quantitatively estimate risks. Then the proposed approach integrates explicitly safety barriers, considered as key parts for risks prevention, and modeled by means of Bayesian networks. Finally a barrier example is depicted in the paper to highlight the feasibility of the methodology