A CPU of a management computer sets an nth component in a mounting operation order of the current sequence as a target component, calculates nearby state data of the target component, sets the required accuracy of the target component based on the nearby state data and memorizes the required accuracy of HDD. Because the required accuracy is automatically set based on the nearby state data in this manner, the set required accuracy matches actual circumstances better compared to than with conventional technology. Therefore, it is possible to automatically set appropriate required accuracy of a target component.