Abstract: The invention relates to a method for the preparation, treatment and updating of tool data sets which is universally applicable and enables variable automatic updating of said tool data sets. According to the invention; a numerical control system is provided with at least one tool data management module which is separate from said control system and which is filed in the memory of an EDP system. The tool data management module contains tool data sets for various tools and has room for static and dynamic data for each tool to be used, i.e. data which undergoes modifications in the numerically controlled processing system. The tool data module consists of separate list data sets of a processing process, said data sets being able to respectively contain a reference to the associated tool data set; and the required list data sets are transmitted together with the associated tool data sets for carrying out said processing in the numerically controlled processing unit and stored.