Abstract: A transfer machine comprising a conveyor for conveying workpieces to stations and numerically controlled machine tools disposed at their respective stations. These machine tools are controlled by sequence controllers, which are connected with their respective numerical controllers. All the programs for machining operations are stored in each numerical controller. When some station is in trouble, the normal machine tool disposed at a station adjacent to the station in trouble is caused to execute the program originally assigned to the station in trouble, as well as the program assigned to the normal station itself.