Manufacturing systems in Nigerian plants have experienced varying degrees of yield improvement due to implementation of different strategies. A DiD approach was employed to compare pre- and post-intervention yields, accounting for potential confounders such as industry trends and economic conditions. The application of the DiD model revealed a significant 15% yield improvement in plants implementing advanced manufacturing systems compared to those without improvements (95% confidence interval: 7. 2-23. 8%). Advanced manufacturing systems led to substantial yield improvements, with clear evidence from the DiD analysis. Further studies should explore long-term sustainability and scalability of these systems in diverse Nigerian contexts. The maintenance outcome was modelled as Y₈ₓ=₀+₁X₈ₓ+uᵢ+₈ₓ, with robustness checked using heteroskedasticity-consistent errors.
Ezeocha et al. (2003) studied this question.