This study analyzes how data-based educational planning is implemented to improve the quality of learning at an integrated Islamic junior high school (SMPIT) in Bekasi, Indonesia, and identifies the factors that support and hinder it. The problem stems from the gap between the availability of data and its use in educational decision-making. A qualitative case study was conducted involving the principal, the vice principal, and 21 teachers. Data were collected through interviews, observation, and document analysis, verified through source and technique triangulation, and analyzed using the interactive model of Miles, Huberman, and SaldaƱa. Descriptive indicator scores, interpreted with percentage-range categories, were used to summarize the level of implementation. The findings show that implementation is in a transitional stage: data are used in planning, instruction, and evaluation but are not yet systematically integrated. Indicator scores fall in the Good category at its lower range (averages of 64.3 for the planning process and 66.0 for evaluation), except for data use in instruction (60, Fair). Low teacher data literacy, a data-based culture that has not yet formed, and organizational factors were the main constraints, while data-based discussions had begun to emerge. As a single case study, the findings cannot be generalized and do not demonstrate effects on student learning outcomes. Strengthening teacher data literacy, transformational leadership, and a collaborative, evidence-based school culture is needed.