PURPOSE: To prevent occurrence of the lack of assembly parts for car bodies to be refed into an assembly production line when the can bodies drawn out from the assembly production line is refed into the assembly production line.

CONSTITUTION: The information from an information reading means 15, which reads out the production information output from a wireless information medium 13 to be attached to the respective car body 11, and the information from a refeeding information inputting means 18, which inputs an information for production of a car body 11 and the position of the refeeding of the car body 11, are input to a production ordering means 17. By means of the production ordering means 17, the expected arrival time of the car body 11 to be refed to an assembling process station S7 and the time necessary for the quick transportation of the parts to be assembled are compared with each other. In the result, it becomes possible that whether the car body 11 to be refed into an assembly production line 12 arrives at the assembly process station S7 before the arrival of the parts to be assembled or not is judged. Consequently, the lack of assembly parts at the assembly process station S7 can be prevented.