Sleman Saliba

Production optimization and scheduling in a steel plant: Hot rolling mill

Abstract In this presentation we investigate the production scheduling of a hot rolling mill in a steel plant. The production schedule must adapt to strict production rules derived from metallurgic and physical constraints. Successful manual planning requires therefore in practice thorough process knowledge and years of operating experience. In our optimization-based approach, we first build parts of the rolling programs using intelligent heuristics and compose these parts to fully feasible programs by solving a min-cost-flow problem. In a second step, the built programs are scheduled using a mixed integer linear programming formulation in order to obtain an optimal schedule that violates as few order due dates as possible. Finally, we describe how to embed the current system within a standard IT environment, connecting the business level to the plant layer.

Production Optimization and Scheduling across a Steel Plant

Abstract This paper focuses on the planning and scheduling optimization of two processes in steel production, the melt shop and hot rolling. Important steps and challenges of bringing a scheduling model from a conceptual idea to an industrial solution that steers the complete production of a steel plant on a day-to-day basis are covered. Moreover, we discuss the main development steps and the embedding of a mathematical model based solution into a production system. Finally, we present some results based on real-world data from an industrial implementation.