This paper presents an approach to simulate complex hierarchical process chains resulting from large logistics networks in OMNeT++, a discrete event simulation environment designed for communication networks. For this purpose OMNeT++ has been integrated as a new simulation engine into the ProC/B toolset which is designed for the analysis and optimization of large logistics networks. The paper highlights the main steps of the automatic transformation of a hierarchical process chain model into a hierarchical model in OMNeT++. Furthermore it shows how the transformation has been validated and how detailed performance figures can be evaluated with OMNeT++. Categories and Subject Descriptors I.6.5 [Simulation and Modeling]: [model development] General Terms Design, Performance Keywords OMNeT++, DES, ProC/B, Logistics