In this article, a novel approach to computer optimization of CNC toolpaths by adjustment of cutting speed vcand depth of cut apis presented. Available software works by the principle of adjusting feed rate on the basis of calculations and numerical simulation of the machining process. The authors wish to expand upon this approach by proposing toolpath optimization by altering two other basic process parameters. Intricacies and problems related totheadjustment of apand vcwere explained in the introductory part. Simulation of different variant of the same turning process with different parameter values were conducted to evaluate the effect of changes in depth of cut and cutting speed on process performance. Obtained results were investigated on the account of cutting force and tool life. The authors have found that depth of cut substantially affects cutting force, while the effect of cutting speed on it is minimal. An increase in both depth of cut and cutting speed affects tool life negatively, although the impact of cutting speed is much more severe. An increase in depth of cut allows for a more significant reduction of machining time, while affecting tool life less negatively. On the other hand, the adjustment of cutting speed helpsto reduce machining time without increasing cutting force component values and spindle load.