Manufacturing plants in Ghana have been identified as potential sources for yield improvement studies. Panel data will be analysed to assess the impact of system modifications on yields. Robust standard errors will be used for inference. A significant proportion, estimated at 15%, of plants showed improvement in yield after system adjustments. System improvements led to measurable gains in productivity, with robust statistical confidence. Further studies should consider scaling up these interventions across more manufacturing sectors. Manufacturing systems, panel data analysis, yield improvement, Ghana The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.