Abstract
This paper explains how decision-making unconsciously influenced by psychological factors can lead to wrong judgments or decisions with illogical thoughts. In a project, decision-making is made not only by a project manager, but also by each team leader engaged in solving problems in a review session or task team. Furthermore, as the project scale expands, the decision-making authority is delegated to team leaders and they are required to make their own decisions. Considering these circumstances, I would like to propose the efficient and accurate process of decision-making based on my experience.
