{ "background": "Ethiopia's industrialisation strategy prioritises manufacturing sector growth, yet systematic, plant-level evaluations of cost-effectiveness to inform policy are scarce. Existing analyses often fail to account for the hierarchical structure of plant data, where operational units are nested within firms and sectors, potentially biasing results.", "purpose and objectives": "This policy analysis evaluates the cost-effectiveness of manufacturing plant systems in Ethiopia. Its objective is to quantify the influence of multilevel factors—plant operations, firm management, and industrial sector—on production costs, providing an evidence base for targeted industrial policy.", "methodology": "A multilevel regression model is employed, analysing a novel, proprietary dataset of manufacturing plants. The core statistical model is specified as $Cost{ijk} = \\beta0 + \\beta1 X{ijk} + u{j} + v{k} + \\epsilon_{ijk}$, where $i$, $j$, and $k$ index plants, firms, and sectors respectively. Inference is based on robust standard errors clustered at the firm level.", "findings": "The analysis reveals that firm-level management practices explain approximately 40% of the variance in plant-level cost efficiency, a substantially larger share than sector-specific effects. A one-standard-deviation improvement in integrated maintenance systems was associated with a 15.2% reduction in unit production costs (95% CI: 12.8% to 17.6%).", "conclusion": "Cost-effectiveness in Ethiopian manufacturing is predominantly driven by intra-firm factors rather than broader sectoral characteristics. This indicates that policies focusing solely on sectoral support may be less effective than those enhancing firm-level managerial and technical capabilities.", "recommendations": "Industrial policy should shift towards programmes that build firm-level operational excellence, particularly supporting the adoption of integrated plant systems and predictive maintenance. Incentive structures should be redesigned to reward firm-internal efficiency gains across all industrial sectors.", "key words": "Multilevel regression, cost-effectiveness, manufacturing systems, industrial policy,