Thermal spraying is an efficient process for producing surface coatings that have improved corrosion and wear properties. In modern injection processes, robots are used, which enable higher productivity and piece quality. However, there are some difficulties with robot programming when the part geometry becomes very complex. In order to improve the robot programming procedure and accordingly increase the quality and economy of the process, a research program was set up in which the thermal spray process was simulated. The off-line simulation of the trajectories of the spray guns, the thickness distribution of the layer and the temperature distribution on the substrate were included. This paper presents the simulation procedure. It also presents some examples with numerical results that showed an improvement in the coating procedure. Paper includes a German-language abstract.