Free and open source fault tree analysis tools survey

Abstract

This paper gives an in-depth survey about some free and open source tools for Fault Tree Analysis (FTA), which is one of the most used techniques in safety and reliability engineering. We have carried out a comparative study for four different tools. Firstly, OpenFTA is an open source fault tree analysis which is based on XFTA calculation engine. Secondly, OpenAltaRica platform which is a free tool that analyzes the risk of complex systems. Thirdly, ALD Fault Tree Analyzer which is a free web-based tool that analyzes static fault trees. Finally, DFTCalc which is an open source tool that analyzes dynamic fault trees based on Stochastic Model Checking techniques. To compare these tools, three representative examples are used. The first one, modeled by OpenFTA and ALD Fault Tree Analyzer, is an Electro Mechanical Actuator (EMA) used to actuate the ailerons of an aircraft, with a static fault tree containing AND gates representing redundancy mechanism. The second, modeled by DFTCalc, is a remotely controlled lawnmower with a dynamic fault tree. The third, modeled by OpenAltaRica, is an example of fault tree generation from AltaRica code. In addition, the same example of EMA system has also been modeled by Isograph Fault Tree++ in order to compare free and open source tools with some commercial tools.