{ "background": "Municipal infrastructure asset management in many developing nations is hampered by a lack of robust, quantitative methods for evaluating the cost-effectiveness of implemented systems. This creates significant challenges for evidence-based investment and policy decisions within civil engineering and public works departments.", "purpose and objectives": "This case study aims to methodologically evaluate the impact of a formalised municipal asset management system on infrastructure maintenance costs in a Ghanaian context. Its primary objective is to determine the system's cost-effectiveness using a quasi-experimental analytical design.", "methodology": "A difference-in-differences (DiD) model was employed, comparing cost trajectories in municipalities that adopted the asset management system (treatment group) against a matched control group that did not. The core econometric model is specified as $Cost{it} = \\beta0 + \\beta1 Treati + \\beta2 Postt + \\delta (Treati \\times Postt) + \\epsilon_{it}$, where $\\delta$ is the causal effect of interest. Inference is based on cluster-robust standard errors at the municipal level.", "findings": "The analysis indicates a statistically significant reduction in annual maintenance expenditure attributable to the asset management system. The DiD estimator, $\\hat{\\delta}$, shows a cost reduction of approximately 18% (95% CI: 12% to 24%) for adopting municipalities relative to the control group, after controlling for underlying trends.", "conclusion": The formalised asset management system proved to be a cost-effective intervention for municipal infrastructure in the studied setting. The quasi-experimental design provides credible causal evidence of its financial benefit.", "recommendations": "Municipal authorities should prioritise the implementation of structured asset management systems, supported by longitudinal data collection to enable rigorous performance monitoring. National policy should encourage the adoption of such systems, potentially incorporating DiD or similar techniques for programme evaluation.", "key words": "asset management, difference-in-differences, cost-effectiveness, municipal infrastructure, maintenance expenditure,