in an external simulation unit the latter having a data systems connection to the industrial machine by means of an intranet and or an internet connection application_number US 92126005 A description the method sequence 1 illustrated in fig1 is known according to the prior art for the fabrication of complex parts the complex parts i e parts workpieces which require processing in a plurality of steps 11 12 13 are modeled in a cad computer aided design system 3 instead of or in addition to the cad system 3 it would also be possible to use a cam computer aided manufacturing system the cad system 3 generates together with a post processor the parts programs 5 which are necessary for the processing of a workpiece the parts program 5 is a nc program for the entire operation of the processing of for example a workpiece it is possible to generate a single nc program 5 and or a plurality of nc programs 5 with a plurality of tool changes however it is also possible to generate a separate nc program for each tool the processing with a tool corresponds to a subprocess the nc programs 5 are then tested with a verification system 7 the verification system 7 has for example nc verification software vericut u00ae is an example of such verification software in the verification process in particular collisions with clamping of the workpiece for example in a tool machine and the workpiece are checked at the same time an erosion simulation is used to check whether the nc programs produce the desired workpiece geometry that is.