Stochastic modelling of delay propagation in large networks

Using analytical procedures to compute the propagation of delays on major railway networks yields sizeable computing time advantages over Monte Carlo simulations. The key objectives of this paper are to present a formalisation of delay propagation by means of an activity graph, to outline the required mathematical operations to traverse the graph and to elaborate a suitable class of distribution functions to describe the delays as random variables. These cumulative distribution functions allow to be speedily computed but also allows the quality of the computing process to be controlled. Last but not least, issues of procedural theory that arise in the context of networks are elaborated and the translation of the approach to a software tool is presented. (C) 2012 Elsevier Ltd. All rights reserved.