A multi-vessel quay crane assignment and scheduling problem: Formulation and heuristic solution approach

Keywords: Quay crane assignment Quay crane scheduling Genetic algorithms Integrated models a b s t r a c t This paper presents a new approach to analyze the integrated quay crane assignment and scheduling problem (QCASP). The problem determines the assignment of quay cranes to vessels and the sequence of tasks to be processed by each quay crane simultaneously, and accounts for important considerations such as safety margins between quay cranes (QCs), ordering conditions and vessel priority. Furthermore, QCs can travel from one vessel to another vessel whenever tasks are complete. The integrated problem is difficult to solve with exact methods due to its complexity. Therefore, a genetic algorithm (GA) is proposed to solve the integrated QCASP. Computational results validate the performance of the proposed GA. International trade plays a crucial role in global economy and it relies heavily on maritime transport, which accounts for approximately 90% of global trade transport (International Chamber of Shipping, 2014). The continuous increase of maritime transport has led to the containerization of goods, which facilitates the growth of this sector, making it an even more important component of international trade. Ports and container terminals are vital nodes in the network as they accommodate the transshipment of goods and then connect them to the rest of the transport network. Fig. 1 shows that global container traffic, as measured in twenty-foot equivalent units (TEUs), has more than doubled between 2001 and 2010. Port operation involves a sequence of activities that require careful planning and execution to ensure maximum container throughput. Upon arrival at the port, the vessel will be assigned to a berthing position, where the offload and upload operations of containers are performed. Following the assignment of a berth, the vessel's containers are discharged by assigned QCs according to a work schedule, and distributed to one of the storage blocks in the yard. The containers are then delivered by internal transportation to truck and train operation areas, where the containers are loaded onto trucks and/or trains to be transported to desired destinations. The operations that take place before the container reaches the storage yard are referred to as quayside operations, as they take place near the quay of the container terminal. Operations taking place on the yard, where containers are stacked and stored, are known as yard side operations. The cost of constructing berths and operating equipment such as the QCs is extremely high. Therefore, …