Strategies for Sustainable Maritime Shipping: a Case Study on Volumetric Fill Rate Optimization

Maritime shipments are responsible for the shipping of 90% of cargo transports in terms of volume globally. Although ocean container shipment is the preferred shipping mode in terms of environmental footprint, sea transport is still responsible for 808,5 MtCO2e/year accounting for 21% of the total contribute of logistics carbon emission. The European Union acknowledged the contribution of the transport sector to climate change and included maritime shipments to its cap-and-trade Emission Trading System. Therefore, methodologies to reduce the environmental impact of maritime shipping are required. This needs to be achieved while ensuring that the costs of ocean container shipments remain competitive compared to alternative transportation modes that offer quicker delivery times but have greater environmental consequences. A potential solution to contribute to the reduction of the environmental impact of ocean freight is optimizing volumetric fill rates, which aims to minimize empty container space and decrease the number of total shipments. This reduction in empty space allows for fewer containers to be shipped, thereby lowering shipping costs, emissions associated with the tare weight of the container, and overall emissions— in a win-win scenario between the economic and environmental dimensions of sustainability. This thesis thus aims to evaluate the impact of volumetric fill rate optimization on the environmental performance of ocean freight shipping, while tracking the economic and time performance of shipments. The work started by analyzing the time windows available to consolidate shipments to increase the volumetric fill rate of containers. The consolidation window is defined as the desired arrival date of the goods at destination minus the goods ready-date at the factory minus the total expected lead time. This time span represents the number of days available to consolidate the shipments and release them in batches, increasing the amount of goods released in a single consolidation cluster thus increasing the volumetric fill rate of the shipped containers. The heuristic methodology is applied to a case study involving an intercontinental shipping lane for ski and motocross helmets. Results display a reduction of CO2e emissions of 12% in the Heuristic Optimization scenario compared to the as-is scenario, maintaining the on-time service level at 100%. A tradeoff between time service level and environmental sustainability was observed, as the organization faces the decision to keep consolidating their shipments, hence maximizing container fill rate, or to release the container to comply with the on-time business targets of the company. The methodology can be used for all shipment release problems where all the orders are placed at one time, leaving room for evaluating possible consolidation clusters and maximizing container volumetric fill rate. The examined case study focuses on a single lane but the methodology is easily adaptable in case of different origins and destinations as well as multiple producers and multiple clients. Results in applying this methodology can be variable, depending on the current state of the order release policy and the size of the consolidation windows. Overall, the best results can be achieved by those companies shipping light weight goods where the tare of the container has a greater relative impact with respect to the total weight of the shipped goods.