Setting up a virtual model of a production system is time-consuming and requires expertise in the use of simulation software as well as knowledge of the operations in production systems. For this reason, the creation of virtual models as a basis for the Digital Twin of a production system is hardly feasible for many companies. This chapter presents an approach for the efficient generation of simulation models. For this purpose, production systems are first systematically described using an ontology. On the one hand, this description serves to develop a generic creation method. This is necessary to be able to convert any production system into a virtual representation. On the other hand, the ontology provides a structured data model for subsequent modelling of the Digital Twin. In this chapter, an approach is introduced for generating a simulation model of the shop floor, including its functional behaviour as well as a visual representation. Since most steps of the approach are automated, the simulation model can be generated highly efficient. Also, less expertise in handling simulation programmes is needed. The remaining manual steps require either no special IT knowledge or can be carried out via services.