This paper describes the sub-package problem in the building construction project which is defined to combine various resources under some constrained conditions and multipurpose. Multipurpose includes the term of works, the cost, the quality, the safety, and so on. Various resources include the labor, the material, and the temporary facilities and machinery, etc. The sub-package is currently arranged through the personal judgment of the site manager. However, this way of arrangement comes to the limitation. In this paper, the methods of the sub-package in construction firms are collected through interviews and surveys. Then, the decision-making support system of the sub-package is developed to achieve the optimization with mathematical programming model where the evaluation criteria are the overhead cost and the management time in sub-package problem.