In the early 2000s, the Québec government joined the international movement in new public management by adopting accountability policies, results-based management (RBM), and the systematic collection and analysis of multisource data to regulate and improve its education system. This study reports on one initiative involving the members of a professional learning community (PLC) in a francophone-sector secondary school in the province of Québec, Canada. Planned organizational change was introduced through the development of a pedagogical decision-making process supported by local multisource data. The project took place over a 10-month period in 2019-2020. The analysis of the semi-structured interview data was inspired by the 3 stages of Lewin's (1947) change management model: unfreeze, introduce change, and refreeze. In total, five main themes were identified: complexity of the data collection and analysis process, multiplicity of the data management software and storage platforms, process implementation, process experimentation, and process sustainability. Outcomes of the planned organizational change include gains in both time and the optimization of the data collection and analysis process, and an improved sense of efficacy and accountability on the part of the teachers toward their students' success.