Tolerance analysis is one of the most important parameters affecting the quality and production costs of a product. In this research, using the tolerance analysis capabilities in Inventor software to set the tolerance of the speed reducer gearbox. First, the dimensions of the conical rotor of the elevator gearbox were obtained by Geomagic reverse engineering software, and then the results were used in Inventor software to develop the gearbox model into a three-speed gearbox. Dimensional and geometric static tolerance analysis of this collection was done by using the worst-case, sum of square roots, process capability index and sigma methods. The results showed the worst-case method in tolerance analysis works more cautiously than other methods, as well as the residual sum of squares method, shows less laxity and interference than the worst-case method. Process index method, confirmed the assembly and in the sigma method, the sigma function considers the level of tolerance to be acceptable. Also, to ensure the correctness of the obtained tolerances, dynamic analysis has been done by using ADAMS software. The results showed that the set did not have any excessive slack or interference during movement. For validation, the results of this study were compared with Monte Carlo simulation results and showed good agreement. تفاصيل المقالة