PURPOSE: To increase the efficiency of a production line for a many-kind and small-quantity production by calculating the optimum operating order of each machine installed for each operation process and carrying out the indication and control of operation, in a many-kind mixed production line.

CONSTITUTION: Information on production, such as, the procedure of operation, using machine, operating time, etc. is previously stored in a controller 10, which calculates the optimum operating order of parts based on a production plan from a host 11 and indicates to an output device 9 as an indication of operation while registering the calculated order in the host 11. According to this indication of operation, parts are delivered out of a parts warehouse 1, arranged in accordance with the optimum operating order by means of an arranging device 2, and sent to each machine 5 through a conveying line 3. Each detector 8 reads distinction information and gives a take-in indication to a loader 4. When machining is completed, a product is sent out onto the conveying line 3 by means of an unloader 6 to be sent into a warehouse 7 for completed products.