The safety and reliability of operation of industrial manufacturing processes is a very important prerequisite for economic production. Process disturbancessuch as collision, overload, breakdown and tool wear are not yet fully understood, and cause production-system failures. In order to prevent the effects of excess wear or eventual tool breakdown, modern technological systems pay particular attention to predicting the condition of tool. Numeroustheories of monitoring have tried to classify and explain tool wear, but none have given completely satisfactory results as yet, while at the same time ensuring flexible, simple and cost-effective process control. The open structure of modern digital control opens up new possibilities: in many cases the combination of digital plant signals and the internal data of the machine control system, along with advanced methods of signal analysis, can replace external control systems. The integration of a process-control software moduleinto the machine control system allows fast reactions, should there be any process disturbances, without any additional hardware expansion. This paper studies the sensitivity of signals contained in the control system to the cutting-tool wear processes in face turning.