Abstract: This paper presents improved methodology of the virtual simulation of turning and milling technological process of the selected components in the graphical interface of CAD/CAM system CATIA V5. Each technology of machining must be supported by selection of the relevant geometry of cutting tools and cutting materials. The technological system CNC machine tool – progressive cutting tool – work piece – fixture must ensure sufficient stiffness, which has a direct influence on the quality of the surface finish of the final product. This technological process is important to enter the process of manufacturing of various precision engineering components of complex shape designed for the needs of automotive and aerospace industries. Using the highest level of programming through graphical engineering system is designed for creating the ISO programs using CNC machine tools. All simulations of cutting experiments show that the proposed clear-up tool path works well in the real cutting process and can improve the machining efficiency of the machining process. At the same time, the manufacturing must have the advanced process equipment and method due to the requirements of the design performance and machining efficiency. Then, the total cutting volumes of an impeller are conventionally machined by (CNC) machine that is set up.