District hospitals are critical nodes in sub-Saharan African health systems, yet systematic assessments of their operational reliability remain scarce. Current evaluations often focus on isolated inputs rather than the complex interaction of infrastructure and governance factors that determine consistent service delivery. This study aimed to develop and apply a methodological framework for quantifying district hospital system reliability in Senegal, identifying the relative contribution of infrastructural and governance determinants to performance variation. We conducted a multilevel regression analysis of primary audit data from a nationally representative sample of district hospitals. The dependent variable was a composite reliability index (0-100). The core statistical model was $Y_{ij} = \beta_{0} + \beta_{1}X_{ij} + \gamma Z_{j} + u_{j} + e_{ij}$, where $i$ denotes hospitals and $j$ districts, with robust standard errors clustered at the district level. Governance factors, particularly supply chain autonomy, explained a significantly greater proportion of variance in reliability (approximately 32%) than physical infrastructure alone (15%). A one-unit increase in the governance score was associated with a 5.8-point increase in the reliability index (95% CI: 3.2 to 8.4), holding infrastructure constant. The reliability of district hospital systems is more strongly conditioned by governance mechanisms than by infrastructure assets. This underscores the need for integrated investment strategies. Health system strengthening programmes should prioritise interventions that enhance managerial autonomy and supply chain resilience alongside infrastructure upgrades. National policies should adopt multilevel reliability metrics for routine performance monitoring. health systems resilience, multilevel modelling, health infrastructure, health governance, sub-Saharan Africa, Senegal This paper provides a novel, transferable methodological framework for quantifying health system reliability and demonstrates its application, offering empirical evidence on the predominant influence of governance over infrastructure.