Intelligent management of seaside logistic operations at maritime container terminals

Resumen

In general terms, a maritime container terminal is a large infrastructure dedicated to the exchange of freights between sea and land transports within multimodal transportation networks, normally composed by container vessels, trucks, and trains. One of its main objectives is to serve arriving container vessels in such a way that their turnaround time and their associated operations are performed as fast as possible. This involves that those operations starting from the berthing of the vessels until their appropriate service having to be performed efficiently. In this regard, once a container vessel is berthed -according to its particular features (dimensions, stowage plan, contractual agreements, etc.)- along the quay, a subset of quay cranes has to be allocated to it for performing the loading and unloading operations. Hereafter, the containers unloaded from the vessel are transferred to the yard, where they are temporally stored, awaiting for being loaded into trucks, trains, or other vessels in order to continue throughout their route. On the other hand, some transshipment containers may continue their route in the vessel. Therefore, they are moved near to it in order to be loaded. A traditional maritime container terminal is usually structured around three main functional areas, namely, seaside, yard, and landside. The seaside is the part of the terminal in which the vessels are berthed in order to load/unload their cargo by a subset of quay cranes allocated in the quay area. Thus, the logistic operations taking place at that part start from the berthing of the vessel upon to the subsequent movement of its containers to the yard. Those operations have to be efficiently handled in order to satisfy the requirements of the market players implied in this environment (i.e., shipping companies, delivering companies, terminal managers, etc.). This accompanied by the increasing growth of freight transportation within containers and the fierce competition around maritime container terminals force terminal managers to constantly improve the terminal management through innovative technologies and optimization techniques. A poor utilization of the seaside main resources (e.g., berths and quay cranes) directly affects other operations taking place at the container yard (e.g., container arrival/departure schedule, container transshipment management) and land-side operations (e.g., truck container pick-up schedule). Hence, in order to avoid a bottleneck or a slowdown of the terminal operations related with the seaside, that cause a reduction of the terminal productivity and dissatisfaction of their direct clients, becomes essential to address the seaside operations in an intelligent way. The objectives of this doctoral thesis are, on the one hand, to study and analyze those relevant logistic problems arisen at maritime container terminals involving the management of seaside key-resources such as berths and quay cranes. Their efficient use emerges as a relevant factor for improving the overall performance of a maritime container terminal. In order to achieve that objective, we analyze, design, and develop optimization techniques aimed at addressing those decision problems as well as supporting the seaside operation management by means of providing feasible and high-quality schedules in terms of a given objective function. On the other hand, along the development and validation of those techniques, this thesis provides wider insights and procedures within the maritime logistics and operations research. To meet the above-mentioned goals, this thesis is particularly concerned on investigating and assessing some of the most relevant and challenging decision problems arising at maritime container terminals regarding the use of berth and quay cranes. As discussed in this thesis, those problems are NP-hard and suitable methods have to be employed in order to provide high-quality solutions within reasonable computational times that justify and advice their real application. On the other hand, the improvement of some mathematical formulations and their proper reformulation is also necessary for assessing the quality of the solutions provided by means of approximate approaches. Finally, the development of efficient approaches allows to integrate them within functional frameworks aimed at providing complete solutions that consider the interdependencies among the operations. The results obtained in this thesis indicate that the performance of maritime container terminals by means of improving the management of those seaside operations involving the use of berth and quay cranes can be performed through the use of intelligent techniques as those proposed in this doctoral dissertation. This is supported by extensive tests and the use of problem instances based on real-data from relevant container terminals such as Gioia Tauro (Italy) or the terminals at the area of Pearl River Delta (China). Moreover, integration approaches addressing seaside operations at maritime terminals have been proposed. These approaches provide comprehensive solutions by taking into account the interdependencies of the seaside logistic operations. The outline of this thesis follows a compendium of papers structure and is organized as follows. Part I introduces and describes the works composing this doctoral thesis. Concretely, Chapter 1 introduces the context of this dissertation and depicts its composing papers. Chapter 2 presents the goals, methodology, results, and conclusions of this thesis. Finally, Part II encloses the works produced during the thesis as appendices.