Abstract
Author developed the mathematical model to minimize transportation cost between harbors, using the linear programming. This model enables us to study the change of the transportation cost based on the condition of facilities. But when the scale of the transportation grows, the total combination case becomes rapidly huge, and the calculation becomes impossible substantially. Then, in this research, the internal variables concerning transship combination were introduced and the formulation was attempted to save calculation. Finally the introduction effect was tested through a simple harbor network.
