Discrete events simulation of Intermodal terminals operation. Modelling techniques and achievable results

A freight intermodal terminal represents one of the most significant bottleneck in logistic chains. The discrete event simulation is suitable to represent the terminal operations, enabling the identification of strengths and weaknesses. It also permits the evaluation ahead of time the changes that modify organizations or the workability of terminals. In this paper the modelling process is described for a railroad terminal based on the simulation platform Planimate©. This platform is suitable to deal with systems articulated with plenty of data and sub-processes, to be managed in parallel and for synchronized cycles controlled according to a time run. The model is organised according to a hierarchical structure composed by various subsystems: the highest level represents the layout of the terminal; the lower levels represent the operational areas, where the models manage integrated flows and elementary operations. Once the model has been built and is able to work, the achievable results are both in the field of operational management of the terminal (short-term application) and in the field of perspective analysis to check the feasibility and effectiveness of new scenarios, built by combining innovative technologies and operational measures (long-term application). The assessment of present and future scenarios is based on key performance indicators, which the model is able to calculate