Guest Talk: Carlos Budde: Discrete (Rare) Event Simulation for Dynamic Fault Trees with Repairs

Tuesday, November 26, 2019, 4:30pm

Location: RWTH Aachen University, Department of Computer Science - Ahornstr. 55, building E3, room 9220

Speaker: Carlos Budde

 

Abstract:

Fault trees are used in all major fields of engineering.
Dynamic Fault Trees (DFTs) are the most widespread extension, because they can model spare-parts management, common causes of failure, and order-dependent malfunctions. Another essential modelling extension are repairs of basic elements, unless you think it a good idea to throw away your bike after a flat tire. These extensions, necessary to augment the realism of system models, make fault tree analysis quite a bit complicated. That is why flexible analysis methods, such as Monte Carlo simulation, are typical approaches to estimate e.g. system reliability.
However, Monte Carlo simulation has a really long and hard time to estimate these metrics when failures are rare. Moreover, if there is nondeterministic behaviour then Monte Carlo simply doesn't know which way to go—and yes, Dynamic Fault Trees have a lot of that. In this talk I'll show a sound way to analyse repairable DFTs using Monte Carlo simulation. I'll also discuss how can this be extended to study failures that occur with very low probabilities.