A Petri Net based approach for modelling multi-layered distributed protocols N. Sergent This paper presents an original modelling approach which aims to provide probabilistic guarantees on time in asynchronous distributed systems for several important algorithms, like consensus and atomic broadcast. The modelling framework is based on Hierarchical Coloured Timed Petri Nets (HCTPN). Simulation is used not only to find statistical upper bounds on the termination time of these algorithms but also to study the influence of the Fault Detectors parameters and to obtain optimal values for them.