컨테이너 운송 시장에서 물류 프로세스별 공컨테이너 발생 원인과 저감 방안에 대한 연구

Abstract

Since the introduction of rail and inland trucking for cargo transportation, the movement of empty vehicles and freight has been a key issue in managing transportation operation costs and optimization. As container volumes from ocean transport continue to grow, the imbalance of empty container inventories at ports, terminals, and inland depots around the world is worsening, mainly due to trade imbalances between head haul and back haul routes in ocean shipping. Since the 1990s, extensive research has been conducted on empty container repositioning and optimization, aiming to minimize the impact of empty containers on transportation inventory and improve demand forecasting. In much of the previous literature on empty containers, it is commonly recognized that empty container imbalances mainly result from trade imbalances. However, other causes of empty container occurrences and their impact on container transportation remain unclear, often attributed to the inherent and unexpected complexities of ocean container transport. In this study, specific causes of empty container occurrences in container transport, beyond trade imbalances are empirically analyzed through simulation, using available container terminal EDI and inventory data. To achieve a door-to-door understanding of container transport and cargo flow, the transport process is reviewed across seven key stages, including the shipper, consignee, terminal, container yard (CY), and in-transit cargo. Additionally, the container ocean transport process is categorized based on physical movement stages such as delivery, reception, vessel loading and discharging, and terminal gate-in and gate-out operations. After an investigation using available container inventory data and EDI files from the container terminal at the Port of Busan, three primary causes of empty container occurrences were identified : container quantity gap (Quantity), transport process time gap (Time), and the variety of container types and involved players (Variety). These factors collectively contribute to the complex and often unpredictable imbalance of empty container inventories in the container freight market. Each of these causes and their respective impacts on container transport were simulated using a container inventory formula and a virtual case study on inventory imbalance. The simulation implemented the mechanisms behind empty container occurrences and analyzed their effects on export and import container inventory flows. Lastly, this study examined the countermeasures taken by shipping carriers to address empty container inventory imbalances, focusing on the respective causes of empty container occurrences and their impacts on container inventory. In addition, several practical strategies are proposed to mitigate the impact of empty containers on transportation costs and to improve operational efficiency.

Key words : Empty Container, Empty Container Imbalance, Empty Container Imbalance Mechanism, Empty Container Imbalance Lessening Measures