An open-source application to model and solve dynamic fault tree of real industrial systems

Abstract

In recent years, a new generation of modeling tools for the risk assessment have been developed. The concept of "dynamic" was exported also in the field of reliability and techniques like dynamic fault tree, dynamic reliability block diagrams, boolean logic driven Markov processes, etc., have become of use. But, despite the promises of researchers and the efforts of end-users, the dynamic paradox hangs: risk assessment procedures are not as straight as they were with the traditional static methods and, what is worse, it is difficult to assess the reliability of these results. Far from deny the importance of the scientific achievement, we have tested and cursed some of these dynamic tools realizing that none of them was appropriate to solve a real case. In this context, we decided to develop a new DFT reliability solver, based on the Monte Carlo simulative approach. The tool is greatly powerful because it is written with Matlab ^® code, hence is open-source and can be extended. In this first version, we have implemented the most used dynamic gates (PAND, SEQ, FDEP and SPARE), the existence of repeated events and the possibility to simulate different cumulative distribution function of failure (Weibull, negative exponential CDF and constant). The tool is provided with a snappy graphic user interface written in Java ^® , which allows an easy but efficient modeling of any fault tree schema. The tool has been tested with many literature cases of study and results encourage other developments.