Production simulation is an established method in the discrete manufacturing industry and became common in the process industry in recent years. This method can be employed for performance measurements and capacity assessments of manufacturing, material and information flow processes. Applications include for example bottleneck analysis, assessment of investment decisions and the solving of sequencing problems. The paper gives a brief summary of the history of the method and describes the most significant basics. Beside a general overview on existing process industry activities the different kinds of applications of production simulation at Degussa AG are explained. The paper finishes with cost-benefit reflections and perspectives on further simulation activities at Degussa AG.