Iterated Local Search for Steelmaking-refining-Continuous Casting Scheduling Problem

Steelmaking-refining-Continuous Casting (SCC) scheduling is an important industrial scheduling problem, which is also a NP-hard combinatorial optimization problem. Efficient SCC scheduling methods can significantly improve the productivity efficiency. In this paper, an efficient Iterated Local Search (ILS) algorithm is devised for SCC scheduling. The ILS starts from an initial solution with certain quality, then executes a multiswap-based local search, subsequently carries out a cycle of perturbation with probability, neighborhood changing, Simulated Annealing (SA)-based local search, and acceptance criterion until termination condition is reached. The SA-based local search is devised to enhance the local search ability of the ILS, while the perturbation with probability is designed to guide the search to a promising area. Comparison experiments with several scheduling algorithms have shown the strength and effectiveness of the ILS.