District hospitals in Ethiopia face challenges to ensure reliable service delivery due to varying system efficiencies. A mixed-methods approach combining quantitative data from surveys (n=500) and qualitative interviews (n=20), with statistical modelling of system performance using logistic regression. System reliability was found to be moderately high ($OR = 1.4, CI: [1.2-1.6]) in treating common ailments compared to complex surgical cases. The evaluation highlights the need for targeted interventions focusing on improving diagnostics and patient flow management. District hospitals should prioritise diagnostic accuracy and streamline referral processes to enhance overall system reliability.