Analysis of the planning activity in the planning department of German hard coal mines have shown that in some branches of the planning process productivity and creativity of the involved experts can be increased, potentials for rationalization be opened up and the cooperation between different engineering disciplines be improved by using computer network systems in combination with graphic systems. This paper reports about the computer-supported planning system 'Grube', which has been developed at the RWTH (technical university) Aachen, and its applications in mine surveying, electro-technical and mechanical planning as well as in the planning of ventilation systems and detailed mine planning. The software module GRUBE-W, which will be in future the centre of the working place for the mine ventilation planning of the Ruhrkohle AG, is discussed in detail. (orig.).