This study aims to evaluate the effectiveness of secondary school systems in Tanzania by analysing panel data. A time-series analysis was employed to assess the performance and efficiency of secondary education institutions. Panel data from multiple years were used to ensure robust conclusions. Significant variations in student achievement were observed across different regions, with a notable drop-off rate in performance over consecutive years. The findings suggest that interventions aimed at improving teaching quality and infrastructure are necessary for enhancing educational outcomes. Schools should be provided with adequate funding to improve facilities and training for teachers. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.