본 연구는 시스템 다이내믹스(System Dynamics)를 활용해 한중일 운항선박의 효율성을 살펴보며, 이 구간 내 운항중인 실제선박을 모델로 투입하여 TEU단위당 비용을 확인하였다. 인천항, 부산항을 중심으로 중국 상해항, 일본 동경항 항로에 316TEU급 선박, 1019TEU급 선박, 1740TEU급 선박을 투입하여 한중일 피더항로에도 규모의 경제가 발생하는지 분석하였다. 선박운항 변수로는 선박속도, 용선료, 유류비, 화물소석률을 선정하여 그에 따른 변동성을 살펴보고 구간별 최적선박을 제시하였다. 연구결과 시스템 다이내믹스 방법을 이용해 운항선박의 각 변수를 투입시켰을 시 구간별 거리에 따라 최적선박이 달라졌으며, 구간이 상대적으로 긴 구간에서 규모의 경제가 발생하는 것을 확인하였다. 또한 상대적으로 용선료, 유류비보다는 화물 소석률 변수가 운항비용에 미치는 영향이 큰 것으로 확인되었다. 연구의 시사점으로는 불안정한 해운시장환경에 맞춰 신속하고 유연한 대처가 필요하며, 외부환경요인에 대한 장기적 모니터링을 실시해 선박투입을 결정할 필요가 있다.
This study researched the efficiency of vessels in the marine transportation markets of Korea, China, and Japan by using system dynamics and confirmed the costs per twenty-foot equivalent unit (TEU) by inputting the actual vessels operated in these routes as models. For routes from Incheon and Busan Ports to Shanghai Port, in China, and Tokyo Port, in Japan, three vessels—one each of 316 TEU, 1,019 TEU, and 1,740 TEU—were input to investigate whether economies of scale occur in feeder routes of Korea, China, and Japan. Vessel speed, charterage, oil expenses, and loading rate were selected as variables of vessel navigation. Fluctuation rate was also researched and the optimal linear per route was presented. When each variable was input through system dynamics, the optimal linear per route varied depending on route distance, and for relatively long distances, economies of scale were experienced. When charterage was set as a variable, the effective vessel from Korea to Shanghai was the 1,019 TEU B vessel. When oil expenses and loading rate were low, vessels with low cargo capacity were effective. When the quantity of goods transported was drastically increased for the Korea, China, and Japan routes, the 1,700 vessel of C Vessel was the most effective. During navigation at the Tokyo Port, B Vessel departing Incheon Port was the most effective in oil price change, followed by C Vessel; B Vessel departing Busan Port was effective. The 300 TEU A Vessel was identified to be a navigation exemption vessel due to its navigation distance of 1,016 miles from Incheon Port. The optimal vessel for oil price change was B Vessel leaving for Shanghai Port; however, it should be a substitute for C Vessel when the charterage and quantity of goods transported between the routes are increased. Regardless of oil price change between these routes, A Vessel had low competitiveness and its transportation unit price would be lower when the vessel lowers the speed considering oil price variability. Concerning the routes to Tokyo Port, the navigation distance from Busan Port was shorter than that from Incheon Port, and therefore, B Vessel was effective, unlike C Vessel.
The cost of each unit depending on the loading rate had a greater effect on navigation expenses than charterage and oil price change. For Shanghai Port, at 100% loading rate, the optimal vessels were C Vessel, B Vessel, and C Vessel. At 50%, B Vessel and C Vessel were effective. A Vessel was more effective at 100% loading rate (300 TEU) than B Vessel at 50% (500 TEU) loading rate. This finding implies that oil expenses and charterage, which are external market elements, were greatly reflected, and therefore, it is not economical. Moreover, for Busan and Tokyo Ports, the navigation distances were shorter than the route of Incheon Port; therefore, B Vessel was effective. When the loading rate of A Vessel was enhanced and its speed was reduced, thus decreasing total navigation expenses, it was more effective for short distances. This study can be helpful to long-term vessel operations on the Korea, China, and Japan routes. Feeder vessel companies are relatively small in comparison to large ones and hence need long-term monitoring, which has thus far been neglected. The former also need prompt and flexible measures to cope with the unstable marine transportation market environment and are required to decide vessel input through long-term monitoring of external environmental factors.