Most technical components applied in industrial practice are subjected to drilling operations during their production process. In conventional processes, the variety of different diameters requires frequent tool changes. Due to its flexibility, circular milling represents a promising alternative to the application of conventional drilling tools for variable process strategies, especially for thin-walled lightweight frame structures. Further advantages are the reduction of the number of tool changes, the reduction of non-productive time, and the increase of manufacturing quality. For the process optimization, an FE-simulation of the cutting operations for thin-walled aluminum profiles is developed. This article describes the investigations regarding the modeling concepts of the mechanical and thermal loads induced into the workpiece during the circular milling process. Furthermore, on the basis of experimental investigations process reliability aspects as well as the correlation of the simulated and the real results will be discussed.