Modeling and optimization of ocean-going unloading problem with stochastic arrival time

One of the important issues which steel enterprises focus on is to reduce the cost occurred in unloading process of ocean-going ship, based on the overseas procurement background of a famous steel enterprise, the unloading problem with random arrival times is investigated in this paper, the cost construction of unloading problem is analyzed and its mathematical models for deterministic and stochastic arrival time are established, respectively. Moreover, Lagrangian relaxation algorithm and genetic algorithm combined with sub-gradient is designed to solve this problem. Finally, some examples are simulated and illustrated to validate the effectiveness and accuracy of the proposed algorithm.