Lightweight structures are an important element in today’s production industry. For the multi-axis milling of these structures some aspects have to be considered to achieve a good surface quality and to prevent damaging the milling machine during the machining process. In this article methods to determine suitable feed rates for the milling process, to identify parts of the workpiece with too much heat build-up, and to avoid collisions between workpiece and machine parts are presented. For this purpose a milling simulation based on a multi-dexel field workpiece model has been developed, in which two types of feed rate adaptation have been integrated. Work on a built-in temperature development simulation and collision control is in progress.