Opportunity-Maintenance-Based Scheduling Optimization for Ship-Loading Operation Systems in Coal Export Terminals

As important nodes of the global coal supply chain, coal export terminals bear the tasks of coal storage, processing, and handling, whose efficiency and stability are of great importance with the growing coal shipping market in recent years. However, poor working conditions of the handling equipment in the coal export terminal, together with its relatively fixed layout and poor flexibility, allow frequent equipment failures to seriously affect the ship-loading operations. To solve the problem, this paper constructs a scheduling optimization model for ship-loading operation systems considering equipment maintenance and proposes an opportunity-maintenance-based two-layer algorithm to solve the model. The upper layer aims to optimize the scheduling scheme of the ship-loading operation system under a certain maintenance plan. The lower layer of the algorithm, an opportunity-maintenance-based “equipment-level–flow-level” maintenance optimization method, determines the best equipment maintenance plan. A coal export terminal in China is employed as the case study to verify the effectiveness of the proposed method. The results show that the proposed method can reduce the average dwell time of ships at the terminal by 15.8% and save total scheduling and maintenance costs by 10.3%. This paper shows how to make full use of equipment failure historical data and integrate equipment maintenance schemes into the scheduling problem of the ship-loading operation system, which can effectively reduce the impact of equipment failures on ship-loading operations and provide decision support for coal export terminal management.