Manufacturing plants in South Africa face significant operational inefficiencies that impact productivity and cost-effectiveness. A randomized field trial was conducted among ten randomly selected manufacturing plants in South Africa. The study employed statistical modelling techniques to assess system performance and costs. The implementation of targeted process optimization measures led to an average reduction in operational costs of $15,000 per month across the sample. The randomized field trial demonstrated that specific interventions can significantly enhance cost-effectiveness in manufacturing plant operations. Manufacturing firms should consider implementing similar cost-saving strategies based on this study's findings. The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.