Advanced Fault Tree Analysis for Improved Quality and Risk Assessment

Abstract

Traditional fault tree analysis (FTA) has formed a common language for the modelling and analysis of risks of complex systems. The approach can be used for a large variety of cases, and several tools exists for the method. Advanced FTA is needed to apply the FTA approach also for dynamic systems with time dependent activities. The traditional FTA is extended by including for example modelling and simulation of operation or phase changes of the systems, stochasticity and delays of relations, and maintenance actions for the components. The rules between the failures and other simulated properties are defined by including Java-based scripts to the model. This allows a great freedom to model any type of dynamic situations. A tool named ELMAS has been created to make the use of the advanced FTA approach as straightforward as possible. It allows to model the static and simple relations by using the traditional FTA method. Complex and dynamic relations are included by using modules that can be freely defined based on the needs of the case.