Manufacturing plant systems in Ethiopia have been identified as critical components for economic development. However, there is a need to evaluate their operational efficiency and identify areas for improvement. A theoretical model will be constructed based on econometric principles, specifically employing the DiD method to analyse changes in manufacturing plant efficiency before and after policy interventions. This model will account for potential confounding factors using robust standard errors to ensure accurate inference. This theoretical framework provides a robust method for evaluating manufacturing plant efficiency and can inform future policy decisions aimed at enhancing economic performance. The findings suggest that policymakers should prioritise investment in technology and training to maximise the benefits of DiD interventions, thereby driving sustainable growth in Ethiopia’s industrial sector. The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.