The Nigerian energy sector is characterized by a variety of manufacturing plants that utilise different systems for efficiency optimization. A mixed-methods approach combining quantitative data collection with qualitative analysis was employed. Randomized field trials were conducted at six representative plants across different regions, where efficiency metrics such as production rates and resource utilization were recorded over a period of three months. During the trials, there was an observed average increase in production rates by 15% compared to baseline conditions, indicating significant improvements due to system upgrades implemented in the trial groups. The randomized field trials demonstrated that targeted system modifications led to substantial efficiency gains. Future research should explore scalability and long-term sustainability of these interventions. Nigerian energy sector policymakers are encouraged to implement similar systematic evaluations to identify and adopt efficient manufacturing plant systems, thereby improving overall sector performance. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.