Multi-buffered steelmaking production scheduling with heuristic rules and memetic algorithm

Aiming at the characteristics of multi-buffer and multi-constraint within the production of steelmaking-continuous casting, a batch-based scheduling approach comprised heuristic rules and memetic algorithm was proposed. By using unit-specific event-point continuous-time representation, a mixed integer linear programming model was built and thus three types of buffers were refined which included finite capacity, infinite capacity, and infinite stocking after processing. Two heuristic rules were proposed, the in-batch was utilized for ensuring the smoothness of production by allocation of these buffers, and the between-batch was employed for satisfying the setup constraint between two successive batches by timing. The memetic algorithm was designed, in which the in-batch and between-batch rules were integrated in the initialization and decoding process respectively and a composite matrix-based variable neighborhood search method was exploited for local optimization. Experimental studies of one given case and several randomly generated instances demonstrated the effectiveness and competence in local exploration and global optimization. © 2015, CIMS. All right reserved.