A multi-level stress test methodology: application to six critical infrastructures in Europe

In the context of the STREST project (http://www.strest-eu.org/), an engineering multi-level risk-based methodology to stress test critical non-nuclear infrastructures has been developed. This paper summarizes the STREST framework and its exploratory application to six key representative Critical infrastructures in Europe, exposed to variant hazards, namely: a petrochemical plant in Milazzo, Italy, large dams of the Valais region in Switzerland, hydrocarbon pipelines in Turkey, the Gasunie national gas storage and distribution network in Holland, the port infrastructure of Thessaloniki, Greece and an industrial district in the region of Tuscany, Italy. According to the characteristics of each case study, different stress test levels were applied. The application to the selected CIs is presented following the workflow of the methodology, comprised of four phases: Pre-Assessment phase; Assessment phase; Decision phase; and Report phase. First the goals, the method, the time frame, and the appropriate stress test level to apply are defined. The stress test is performed at component and system levels and the outcomes are checked and compared to the acceptance criteria. A stress test grade is assigned and the global outcome is determined by employing a grading system. Finally, critical events and risk mitigation strategies are formulated and reported to stakeholders and authorities.