Model and Solution for Hot Strip Rolling Scheduling Problem Based on Constraint Programming Method

This paper presents a mathematical model and a solution approach to solve the hot rolling scheduling problem. The problem is formulated as a constraint satisfaction problem with various process constraints, and the mathematical model is established by constraint programming conveniently. The purpose of this research is to find a slab sequence in any given slab set. In order to reduce the complexity of solving the problem and improve the solution efficiency, the original problem is divided into two sub-problems: slab-choose problem and slab-sequence problem. The slab-sequence stage is to sort the slabs from the result of the slab-choose stage. The model of the problem is tested with practical production data. Based on the constraint programming, the model is solved quickly. The computational results of the problem show that the method for this model is feasible, and the results meet the requirements of practical applications.