This study builds upon existing research on manufacturing yield improvement in Tanzanian plants by focusing on methodological advancements. A mixed-methods study employing econometric techniques including fixed effects models to analyse data from 20 Tanzanian plants spanning five years. Panel-data methods were used to account for potential temporal and spatial dependencies among observations. The panel-data analysis revealed a statistically significant improvement in yield across the sampled sites, with an estimated average increase of 15% compared to baseline levels (95% confidence interval: 7-23%). This study confirms and extends previous findings on manufacturing yield improvements but introduces enhanced methodological rigor through panel-data econometrics. Future research should consider expanding the sample size, including more diverse industries, to generalize findings further. The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.