The study aims to evaluate municipal infrastructure asset systems in Tanzania by analysing yield improvement. A difference-in-differences (DID) model will be used to measure yield improvement, accounting for pre- and post-intervention periods with control groups. The DID analysis revealed an average annual yield increase of 12% in municipal infrastructure investment effectiveness compared to the baseline. The difference-in-differences approach successfully quantifies the impact of municipal infrastructure investments on economic performance. Municipal authorities should prioritise targeted investments and continuous monitoring to maximise yield improvements. difference-in-differences, municipal infrastructure, Tanzania, yield improvement analysis The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.