Hot Strip Mill Scheduling Problem with considering Hot Charge

This study investigates the Hot Strip Mill Scheduling Problem (HSMSP) which is one of the most important planing problems in the steel industry. The problem is fromulated using the Prize Collecting Vehicle Routing Problem (PCVRP). The new proposed formulation considers more details and more realistic constraints than those used in provious studies. the hot charge technique, along with the omission of slab preheating before hot rolling, leads to considerable savings in energy and other benefits in the process of steel production. the technique is closely related to HSMSP. In our proposed formulation, the necessary provisions required for obtaining an initial level of hot charge have been taken into consideration. A search algorithm has been developed that sonsists of three major phases including separation of slabs that can be scheduled, generation of an initial solution, and improvement of the solution. generation of the initial solution is accomplished using a greedy constraint satisfaction algorithm and solution improvement through a guided local search (GLS). Four methods of Deletion, Exchange, Insertion, and Relocation are applied to generate neighbothoods. proposed model and search algorithm have been tested on random and collected instances from ptactical production data in Mobarakeh steel Complex (MSC), the greatest plate steel manufacturer in Iran. The experimental results in both real and random examples show the high accuray and efficiency of the proposed model and search algorithm.

Keywords:

Hot strip mill scheduling problem , guided local search