Organizational performance remains a key concern in public sector institutions, with Quality Management Systems (QMS), particularly ISO 9001, widely adopted to enhance service delivery and operational efficiency. Despite its widespread adoption, existing s tudies report mixed findings on the extent to which ISO certification contributes to improving organizational performance, indicating the need for further investigation. This study compared the organizational performance of ISO-certified and non-ISO-certified Schools Division Offices (SDOs) in the Department of Education. It also identified implementation challenges and proposed a framework for performance enhancement. A convergent parallel mixed-method design was employed, integrating quantitative and qualitative approaches. Quantitative data were analyzed using descriptiv e statistics and the Mann–Whitney U test, while qualitative data were examined through thematic analysis. Results showed that all five organizational performance dimensions were generally rated as consistently implemented, with Management Responsibility an d Stakeholders’ Participation receiving the highest ratings. However, qualitative findings revealed recurring challenges, including leadership instability, resource constraints, process inconsistencies, limited data utilization, and stakeholder engagement issues. Although ISO-certified SDOs obtained slightly higher mean performance scores than non-ISO-certified SDOs, the difference was not statistically significant, suggesting that ISO certification alone is insufficient to account for variations in organizational performance. The study concludes that organizational performance depends more on the effective implementation of quality management practices than on ISO certification alone. Leadership stability, adequate resources, standardized processes, and evidence-based decision-making are critical determinants of performance. Based on these findings, the study proposes an Organizational Performance Enhancement Framework that promotes continuous improvement, process standardization, and context-responsive quality management practi ces to strengthen organizational performance across Schools Division Offices.

Keywords: ISO 9001, Quality Management System (QMS), organizational performance , Schools Division Offices, public sector, continuous improvement