A hybrid differential evolution algorithm for open-order coil allocation problem in the steel industry

摘要

Open-order coils are defined as the coils which have not been yet assigned to any orders and are stored in the coil storage as surplus inventory. Open-order coil allocation problem is to allocate open-order coils to unfulfilled customer orders in order to reduce surplus inventory and improve the material utilization. We formulate the problem as an integer programming model considering specifications of coils and requirements of orders. Since the problem is NP-hard, an improved differential evolution algorithm (called HDE) is proposed to achieve the near optimal solutions for the problem. In the algorithm, mod mutation operators and a fitness-based mechanism are adopted to perform the global exploration. In addition, variable neighborhood search is embedded to further enhance the local exploitation. Computational experiments based on different scale instances are carried out to verify the effectiveness of the proposed model and algorithm.