A Difference-in-Differences Model for the Cost-Effectiveness Evaluation of Manufacturing Systems in Senegal

"background": "Evaluating the cost-effectiveness of capital-intensive manufacturing systems in developing economies remains methodologically challenging, particularly for isolating the causal impact of specific interventions from broader economic trends. ", "purpose and objectives": "This study develops and applies a quasi-experimental difference-in-differences (DiD) model to rigorously assess the cost-effectiveness of implementing advanced production control systems within the Senegalese manufacturing sector. ", "methodology": "A panel dataset was constructed from operational and financial records of treated and control plants. The core DiD estimator is specified as Y{it = \0 + \1 + \2 + \ (\) +, where Yit is the cost-effectiveness ratio. Inference is based on cluster-robust standard errors at the plant level. ", "findings": "The intervention generated a statistically significant positive treatment effect (\ = 0. 18, 95% CI 0. 11, 0. 25). Plants adopting the new system demonstrated an average improvement in cost-effectiveness of approximately 18% relative to the control group, with effects materialising fully after an initial implementation period. ", "conclusion": "The DiD model provides a robust analytical framework for evaluating engineering system interventions in manufacturing contexts where randomised controlled trials are impractical, confirming the tangible economic benefits of targeted technological upgrades. ", "recommendations": "Manufacturing plant managers should consider quasi-experimental evaluation designs for capital investment appraisals. Policymakers can utilise this methodology to structure industrial support programmes requiring demonstrable impact evidence. ", "key words": "difference-in-differences, cost-effectiveness, manufacturing systems, quasi-experimental design, operational research, industrial engineering", "contribution statement": "This paper presents a novel application of the DiD econometric model to the field of structural and manufacturing engineering, providing a validated tool