Research

Main Topics

Software Development

Olivier Nusbaumer has developed and released a Binary Decision Diagram (BDD) software (NeuralSpectrum),
which was developed during his PhD Thesis "Analytical Solutions of Linked Fault Tree Probabilistic Risk Assessments using Binary Decision Diagrams with Emphasis on Nuclear Safety Applications", Diss. ETH No. 17286, 2007.

NeuralSpectrum is an integrated fault tree / BDD tool that features a fault tree package, a BDD engine and a minimal cutset engine, with dedicated fault tree to BDD conversion and optimization routines. The optimization routines include global, static (pre-processing), dynamic and local (BDD objects) techniques.

Using this tool and techniques, Olivier Nusbaumer succeeded in converting a fullscope linked fault tree model, as found in nuclear power plants, to its BDD form. This was a major achievement, because BDD represent exact solution of such models.

Thanks to its Graphical User Interface, NeuralSpectrum also helps to better understand how such complex mathematical structures look like in practice.

NeuralSpectrum was developed in C# 2005 and is freely available here