Process system including robot that transfers workpiece to process machine

A process system comprising:

• a process machine including a fixture where a workpiece is fixed;
• a robot that transfers the workpiece to the fixture;
• a control device that controls the process machine and the robot;
• and
• a detection device that detects a rotation angle of the workpiece around a predetermined axis line when the robot grips the workpiece, wherein
• the process machine includes a drive device that rotates the fixture,
• the control device includes a storage unit that stores a reference rotation angle serving as a criterion of a rotation angle of the workpiece, and an error calculation unit that calculates a rotation error relative to the reference rotation angle in the rotation angle of the workpiece detected by the detection device, and
• the control device corrects the rotation angle of the fixture based on the rotation error so as to correspond to the rotation angle of the workpiece detected by the detection device when the robot transfers the workpiece to the fixture.