Computer Aided Scheduling for Ore Transfer

Abstract We have developed a scheduling system for ore transfer in the ore yard of a large integrated iron and steel making works. Generally, scheduling the ore transfer from ore yards to ore bins in plants includes the following three states: (1) Determination of ore bins to be supplied. (2) Determination of the site of the ore yards and the conveyors to be used. (3) Determination of the quantity and the time of ore transfer. This scheduling may be regarded as a mixed problem of combinatorial problems and assignment problems. So it seems difficult to make an ore transfer schedule. The scheduling algorithm we have developed is very practical. The whole scheduling interval is divided into several short intervals. By this procedure, it becomes possible to treat assignment problems separately from combinatorial problems. In each short interval, optimum scheduling for the ore transfer is performed using binary matrices and linear programming. These schedules in each short interval are connected in succession and the suboptimum schedule is constructed for the whole interval. The philosophy stated above is reflected in an on-line scheduling system. Further, the scheduling system is provided with the functions needed for an on-line system. Namely, it takes a short time to calculate the schedule and it is easy to reschedule for extraordinary situations.