PURPOSE: To enable efficient scheduling by selecting a lot with high priority order concerning processing out of lots in process, selecting a device short in the time required for processing out of the selected lots and allocating a work.

CONSTITUTION: When an event is generated corresponding to contents in the middle of scheduling stored in a storage device 13, the lot under processing at that time is extracted from the scheduled result stored in the storage device 13. Then, lots with high priority order are successively selected. Concerning the selected lots, evaluation values in respective devices, are calculated by a CPU 10 and the calculated result is stored in the storage device 13. The device with highest evaluation (with shortest time for processing) is selected out of the selected lots, and the work is allocated and stored in the storage device 13. Then, the scheduled result is displayed on a display device 10. Thus, when the event is generated, the work can be efficiently allocated concerning the device to be operated.