Technological ensuring the reliability of machine parts is realized by failing to reach the limited state of the elements of the technological system: machine – clamping device – metal-cutting tool-part. A method of optimization synthesis of parameters of technological processes of manufacturing machine parts has been developed. Testing the developed methodology, it was found that the metal cutting tool is Meanwhile, research has shown that metal cutting machine has the least influence on the formation of detailed quality-adjustable parameters from all the the weakest element of the technological system in terms of reliability and has the greatest impact on the quality of machined parts. elements of the process media "machine – clamping device – cutting tool". Finally, a concrete example is provided to demonstrate the effectiveness of the proposed method. The proposed technique has been successfully tested for the manufacturing process of the reduction-gear housing.