Industrial automation systems are becoming increasingly interconnected as part of Industry 4.0, driving demand for reliable, secure communication within these systems. OPC UA has emerged as the de facto standard for industrial communication, and its recent extension, the publish-subscribe communication model (PubSub), has gained attention for its suitability for scalable, low-latency industrial communication. Few earlier studies have investigated how PubSub can be modelled and represented within discrete-event simulation environments. This study investigates modelling approaches for representing OPC UA PubSub within a discrete-event simulation environment, mapping these to corresponding simulation constructs in OMNeT++, and implementing a simulation model in OMNeT++ that uses OPC UA PubSub timing behaviour. The findings show that OPC UA information modelling is the most common approach to model OPC UA. OMNeT++ has been identified as one of the most common approaches for simulating OPC UA PubSub, and investigating different approaches to incorporate OPC UA PubSub into OMNeT++ led to partial integration. The experimental results show that discrete-event simulation can be used to analyse performance characteristics of OPC UA PubSub. Additionally, this study demonstrates the need for OPC UA PubSub-specific modelling and simulation approaches and shows that timing-based OPC UA PubSub incorporation into OMNeT++ can capture realistic communication behaviour while maintaining scalability and deterministic execution.