Selecting master slab width(s) for continuous steel casting

This research investigates a production planning problem faced by one of the largest companies in the steel industry. The company constructed a continuous caster capable of producing slabs of steel from 92 to 104 inches wide. The planning decision is to select the most economical master slab width(s) from this range. Embedded in this production planning problem is a short-term scheduling problem. Because master slabs are wider than customer requirements and wider than the equipment which processes them, they must be ripped longitudinally. Before selecting the master slab widths, a procedure must be developed to combine various customer order widths to obtain minimum losses when the master slabs are ripped. The author presents a mathematical programming formulation developed to solve this short-term scheduling problem, and then demonstrates its use in solving the production planning problem of selecting the master slab width(s). While the actual results may not be directly applicable to different sets of circumstances, the methodology and its use are important, as demonstrated by the fact that the results obtained from the study have been implemented by the company.