The initiative to implement the "Mobilize Sarakulnawitaya School to Become a 21st-century School" project was part of a broader research program that aimed at improving education in the 21st Century by prioritizing active learning, integrating technology into learning, and by increasing the adoption of e-office solutions. The project was conducted using the Participatory Action Research (PAR) methodology, which involved a cyclical process of Planning, Acting, Observing, and Reflecting (PAOR), with two cycles scheduled to take place during the Academic Year of 2022. It was expected that the implementation of this project would result in the following outcomes: 1) improvement in both the research participants' practices and the school's performance as a 21st-century school by the defined focus areas; 2) learning from the actions taken at the individual, group, and school levels; and 3) the knowledge gained from the implemented actions, which could serve as a model for the continuous development of this school in the future. In this research project, there were 20 teachers, who participated as researchers, and 50 students, who were involved in the development process. The findings revealed the following outcomes: 1) there were significant improvements observed in both the research participants' practices and the school's performance as a 21st-century school, in accordance with the defined focus areas, after the completion of Cycle 1 and Cycle 2; 2) the research team, research participants, and Sarakulnawitaya school learned many aspects, particularly the importance of seeking new knowledge as a way to foster out-of-the-box thinking, which results in more efficient work practices; 3) the knowledge, gained from the implemented actions, demonstrated the cause-and-effect relationship between the driving forces that promoted change, the barriers that hindered it, and the strategies used to overcome those barriers.