Integrated scheduling of rake and stockyard management with ship berthing: a block based evolutionary algorithm

An integrated problem of optimising the operations at a commercial bulk material port terminal is studied in this paper. We simultaneously optimise the stockyard operations and rake schedule for outbound cargo, in conjunction with the arriving vessels and the status of the stockyards at the port. A mixed integer linear programming model for the problem is developed while incorporating the inherent complexities of the integrated model. To solve the real-life instances, two heuristic methods are proposed specifically for the considered problem. Firstly, genetic algorithm coupled with a greedy heuristic and later, block-based evolutionary algorithm (BBEA) is employed. After applying both techniques, we obtain the optimised schedule for loading of rakes and allotment of stockyard space for vessels as well as rakes at the terminal. Finally, we test the results of both models in three traffic scenarios between themselves and with real-life data from a port situated along the Eastern coast of India. The study resulted in significant reduction of turnaround time for rakes at the port terminal, which in turn lead to monetary savings. The model also automates the day to day operational decision-making at the port.