Single-machine scheduling problem in plate hot rolling production

Plate hot rolling scheduling is a type of single-machine scheduling problem with waiting time constraints and finite buffer capacity. The aim is to determine when the plate is rolled, decrease the mill idle time and increase mill utilization. Three scheduling methods, i.e. uniformity alternate scheduling method, symmetry alternate scheduling method and group alternate scheduling method are proposed. For every scheduling method, start rolling time interval and mill utilization formulas are given respectively. Some parameters of the formulas should be adjusted according to the roll table length. Based on the three scheduling methods, a heuristic scheduling approach is proposed for the plate hot rolling scheduling problem. Computation examples demonstrated the application of the heuristic scheduling approach.