{ "background": "The effective management of municipal infrastructure assets is critical for service delivery and sustainable development. Despite policy imperatives, the adoption and performance of formal asset management systems (AMS) by municipalities in South Africa remain poorly understood, with a lack of rigorous empirical evaluation.", "purpose and objectives": "This study aimed to quantify the causal effect of formal AMS adoption on key infrastructure performance indicators across South African municipalities, and to identify the principal determinants of successful adoption.", "methodology": "A quasi-experimental difference-in-differences design was employed, analysing a longitudinal panel dataset of municipal engineering records. The treatment effect of AMS adoption was estimated using a two-way fixed effects model: $Y{it} = \\beta0 + \\beta1 (\\text{Treat}i \\times \\text{Post}t) + \\alphai + \\gammat + \\epsilon{it}$, where robust standard errors were clustered at the municipal level.", "findings": "Municipalities that adopted a formal AMS achieved a statistically significant 18.2 percentage-point reduction in unplanned water infrastructure failures (95% CI: 12.4 to 24.0) compared to non-adopting counterparts. Financial capacity and institutional stability were the strongest predictors of adoption, whereas political cycles showed a negligible influence.", "conclusion": "The formal adoption of structured AMS has a substantial, positive causal impact on infrastructure reliability. However, adoption is highly contingent on internal municipal governance and resource factors, not merely on the availability of technical systems.", "recommendations": "National grant funding for AMS implementation should be conditional on demonstrable institutional readiness. Engineering curricula and professional development must place greater emphasis on asset management principles and organisational change management.", "key words": "asset management, municipal engineering, infrastructure, quasi-experimental, difference-in-differences, South Africa", "contribution statement": "This study provides the first causal evidence, using a quasi-experimental design, on the impact of formal