Currently the trajectories of the cutting tool play an important role in optimizing the manufacturing time and the machining quality (roughness, manufacturing tolerances, etc.).The purpose of this paper is to develop an approach for the manufacturing tolerances optimization under the effect of the cutting tool trajectory. This work is organized around two axes. In the first axis, an experimental study was conducted to determine the cutting tool path with less error. The second axis is devoted to modeling and real-time optimization of the cutting tool path defects. In this section the defects were modeled by the least square edit method.