Schools face a range of complex and diverse challenges that are difficult for teachers to address on their own. In response, since 2015, there has been growing demand to promote the concept of the "school as a team,"whereby teachers and other professionals actively collaborate to support students. However, concrete strategies for building shared cognition, making decisions, and incorporating the opinions of various professionals in schools have not been adequately proposed. To address this problem, this paper proposes a method introducing the ordinal priority approach methodology in multi-criteria decision-making. Furthermore, to discuss how and in what cases the proposed method contributes to interprofessional collaboration in schools, simulations were conducted with two different groups of staff members, using hypothetical cases of students not attending school. In addition, questionnaires were administered to school staff. The results demonstrated that the proposed method has three advantages: 1) it promotes fair decision-making, regardless of status or influence in the team; 2) it helps to visualize the results of the decision-making; and 3) it facilitates shared cognition among professionals through the process of listing and ranking criteria and alternatives. This study's results contribute to the establishment of a concrete strategy for interprofessional collaboration in schools.