# Resource Capacity Requirement for Multi-Terminal Cooperation in Container Ports
## 2 Resource Profiles for Representing Workloads
### Resource Profiles
Figure 1 depicts the container storage and retrieval activities associated with \(C_{a}\), \(C_{b}\), \(C_{c}\), and \(C_{d}\). The resource profiles for \(C_{a}\), \(C_{b}\), \(C_{c}\), and \(C_{d}\) can be represented by cumulative workload distributions. The QC intensity refers to the number of QCs allocated to a vessel and is conditional upon the vessel category and the TEU quantity. The QC intensity affects the unloading and loading rates, and hence, can be used to represent the workload of QCs at the resource profile. Since the yard is a storage space for containers, the number of containers for the accommodation can be straightforwardly regarded as the workload. The truck queue length is a proxy for gate workload. When a mainline vessel arrives, the outbound containers from mainland and the transferred outbound containers from other terminals were stacked in the yard in advance (TEU workload in \(C_{a}\)). The TEUs from the unloading operations of the vessel temporarily increases the TEU quantity in the yard (TEU workload in \(C_{b}\)) as much as the inbound and trans-shipment TEUs. The stacked outbound and transferred containers are loaded onto the vessel and the corresponding TEU quantity (TEU workload in \(C_{c}\)) decreases during the loading operation. A part of unloaded containers can be transferred to another terminal (TEU workload in \(C_{d}\)) for trans-shipment according to the predetermined berth schedules of the terminals. When applying the resource profiles for feeder vessels, as depicted in Figure 2, the resource requirement is relatively simple compared to that of mainline vessels. Since the feeder vessels transport containers plying between trans-shipment and neighboring terminals, there are only unloading and loading operations at a terminal without the need of transferring to another. When a given amount of TEUs are unloaded from a feeder vessel, they are eventually loaded onto a mainline vessel resulting in the increase of TEU quantity in the yard (TEU workload in \(C_{b}^{f}\)). Meanwhile, when a feeder vessel is scheduled to load TEUs from the terminal, a small proportion of total TEUs arrived earlier at the yard (TEU workload in \(C_{a}^{f}\)) from a mainline vessel, and a certain amount of TEUs are loaded onto the feeder vessel (TEU workload in \(C_{c}^{f}\)). Figure 1: Simplified illustration of resource profiles for a mainline vessel. Comparing the unloading and loading processes, the speed of unloading speed is faster at the beginning of operations and subsequently slows down in preparation for the switch to loading operations. The unloading operations, especially for containers on the deck, can usually be done efficiently with a well-designed vehicle dispatching strategy. On the other hand, the loading process is relatively slower because the process needs to consider the loading plan (i.e., terminal-level stowage plan) and ensure the ship's stability and safety. The loading process are also dependent upon the supporting operations of vehicles and yard cranes that need to be carefully sequenced and dispatched. Meanwhile, the hatch cover handling operations, involving the uncovering and covering of the hatch, increases the durations of both the unloading and loading process as the quay cranes switch the spreader to wired hooks.