Simulation in process control. Distributed control systems provide their users with many potential benefits which are exhaustively used only in a small number of applications. Distributed control systems supply process data in real time in a digital format. When processing these data together with process models, the advantages of distributed control systems can be considerably extended. Process models are understood as mathematical systems containing a-priori knowledge about processes in a numerical or logical form. In the context of distributed control systems, some new and exciting applications of modelling and simulation techniques become accessible. Basic concepts of these specific techniques are described in this contribution. A collection of potential and realized applications show that these methods allow for a more detailed observation and for advanced process control strategies.