Concurrent Importance and Sensitivity Analysis Applied to Multiple Fault Trees

Complex industrial systems may present different potentially dangerous failure states (Top-Events). The analysis of system failure states via Fault-tree technique allows determining the failure frequency of potential accidents and the importance measures of components’ failure modes. The combination of Importance and Sensitivity Analysis (ISA) constitutes a very powerful tool to improve the design of critical systems or to prove that the design satisfies safety requirements. The present reports describes a novel approach to implement Importance and Sensitivity analysis applied to Fault-trees, which consists of the concurrent analysis of all relevant system’s Fault-trees to identify the weakest parts of the system which require further design improvement. This approach aims at overcoming the limitations of the current methods in application for ISA in which Top-events are sequentially analysed. In addition the proposed method extends the ISA application also to “over-reliable” system functions (if any) on which the reliability/maintainability characteristics of the involved components can be relaxed with consequent cost saving. The result of the analysis is a uniformly protected system satisfying the predefined design goals. How to obtain EU publications Our priced publications are available from EU Bookshop (http://bookshop.europa.eu), where you can place an order with the sales agent of your choice. The Publications Office has a worldwide network of sales agents. You can obtain their contact details by sending a fax to (352) 29 29-42758. The mission of the JRC is to provide customer-driven scientific and technical support for the conception, development, implementation and monitoring of EU policies. As a service of the European Commission, the JRC functions as a reference centre of science and technology for the Union. Close to the policy-making process, it serves the common interest of the Member States, while being independent of special interests, whether private or national.