Simulation Model of Loading and Unloading Operations in the Rear Zone of a Container Terminal Based on a Finite-State Machine

This article examines the potential for applying digital technologies to the planning and management of local operational processes at a sea container terminal. The object of the study is the technological process of container handling in the warehouse and rear zones of the terminal, including the formation of a dispatch stack for the subsequent transfer of cargo to rail transport. From an operational perspective, the formation of a dispatch stack is a labor-intensive technological operation, as it involves the selective search for and removal of a number of containers from the operational stack that constitute the logistics flow directed to the rear operational zone. The research method is based on automaton-based programming of the sequence of local operations within the simulated technological process of train loading. The modeled object is described by a finite-state machine, which is subsequently transformed into a digital code for each local operation that collectively constitutes the technological process of loading and unloading operations. Since the primary function of the finite-state machine is to implement control, within the framework of this study the control actions are directed at the container-handling machine and program the sequence of its operations, including the removal of target containers from the operational stack, the formation of a dispatch stack in the rear zone of the terminal, and the loading of cargo batches onto railway platforms upon the arrival of a train at the port. The results of the study include a simulation model of loading and unloading operations in the rear zone of a container terminal, as well as state-transition diagrams of local operations for the finite-state machine with corresponding control rules (codes). The application of this mathematical apparatus to process modeling makes it possible to develop a unified control logic for cargo handling operations across the terminal’s operational zones.