As recent merchant vessels are purpose-built and growing in size, the impact of a maritime disaster became more serious. So the mariners are required to execute onboard works without fail. To execute onboard work unfailingly, the mariners are required to exert their techniques adequately. However, there are few examples that clarify the management of mariners' technical exertion. In this paper, authors tried to clarify the function of management in ship operation. On analyzing the function of management, authors proposed the definition of the function of management and organized the content of the function in "4W; what, why, when, who" and "1H; how" conditions. On the basis of the concept of the function of management, authors carried out the experiment and analyzed/compared the maneuvering of experienced mariners and freshman mariners in the ship-handling simulator. As the result of the experiment, the validity of the proposing concept and the importance of the function of management became clear.
