Purpose: Modern companies tend towards the greatest possible automation in all areas. The new control concepts of manufacturing processes required development of adequate tools for the introduction of automated control in a certain area. The paper presents such system for automated programming of CNC machine tools.Design/methodology/approach: The system is based on the previously incorporated know-how and the rules of it implementation in tool – shop. The existing manufacturing knowledge of industry tool production was collected and analysing. On this bases flow chart of all activities were made. Theoretical contribution is made in systemization of technological knowledge, which is now accessible for all workers in NC preparation units.Findings: Utilization of technology knowledge. On the basis of the recognized properties it has worked out the algorithms with which the process of manufacture, the tool and the optimum parameters selected are indirectly determined, whereas the target function was working out of the NC programme. We can first out that with information approaching of the CAM and CAPP the barriers between them, strict so far, disappear.Research limitations/implications: Till now, the system is limited to milling, drilling and similar operation. It could be extended to other machining operations (turning, grinding, wire cutting, etc.) with the same procedure. In advanced, some methods of artificial intelligence could be use.Practical implications: It is suitable for industry tools, dies and moulds production, while the system was proved in the real tool shop (production of tools for casting). The system reduces the preparation time of NC programs and could be used with any commercial available CAD/CAM/NC programming systems. Human errors are avoid or at lover level. It is important for engineers in CAD/CAM field and in tool – shops.Originality/value: The developed system is original and was not found in the literature or in the praxis. Developed method for preparation of NC programs is new and incorporate higher level of automation.