Sustainable Train Discharge in Port Terminals Through Flexible Flow-Shop Scheduling

This paper addresses the train-discharge process in a port terminal while integrating sustainability considerations. Building on prior work that minimized total discharge time, we extend the framework by incorporating machine-level energy consumption and associated CO_2 emissions. Each operational resource is modeled within a flexible flow-shop scheduling setting, total energy is computed as the sum of per-job, per-machine processing energy, and emissions are derived via machinespecific emission factors. Relative to the operators' schedule, the optimized solution reduces makespan by 25%, total energy consumption by approximately 8.5%, and CO2 emissions by approximately 9.6%. These results demonstrate that meaningful environmental benefits can be achieved alongside operational improvements, highlighting the feasibility of integrating sustainability objectives into terminal decision making.