ABSTRACT
The economic development and ability to compete on the international market of major branches of industry in the Federal Republic of Germany is crucially dependent on the ability of enterprises to introduce innovation in products and processes. In the course of the economic development since the postwar period, considerable shifts have occurred in the structure of the labour force. Among the enforced rationalisation measures in mechanical engineering from the mid-1970s the introduction of computer numerical control (CNC) machine tools plays a special role. The use of CNC machines especially affects the mechanical fabrication and the process preparations, in which one group produces the NC programs. With the increased use of CNC machines from the end of the 1970s the work division between programming and machine operation in the heavy part shop was modified. For the NC machine operator the structure of dynamic muscle stress is different from that in conventional machine work.
