1. A system including a plurality of machine tools and a factory monitoring system,the machine tool comprising:
a ball screw configured to connect to the motor such that rotational motion of the motor is converted to linear motion of the ball screw;
a table connected to the ball screw that moves linearly based on the linear motion of the ball screw; and
a control device connected to the motor for detecting a rotational position of the motor and a use frequency within a stroke of the ball screw, the use frequency within the stroke of the ball screw being used for determining uneven wear of the ball screw,
wherein the factory monitoring system detects uneven wear of the ball screw by summing each distribution of the use frequency sent from the plurality of machine tools.