This thesis describes the general maintenance procedure and the detailed maintenance procedure of a multi-operation machining center. All daily, weekly, monthly, quarterly, semi- annual, annual, and biannual maintenance, cleaning, and inspection procedures are listed. Two technological processes for the production of a very complex machine part were designed: one manufacturing process for production on a multi-operation machining center and the other on conventional machining tools. The procedures were compared with each other, and the obtained data was analyzed. The practical part describes the reactive maintenance of a multi-operational machining center in which the damage on the ball screw spindle of the "X" axis was detected, due to which further work with the specified accuracy was not possible. The only possible solution is reactive maintenance of the machining center. The procedure for adjusting the geometry and laser calibration of the machine is described, and the measurement protocol of the product before and after the maintenance is compared.