"background": "Community health centres are critical nodes in primary healthcare systems, yet robust methodologies for quantifying their operational reliability are lacking. This gap impedes evidence-based system strengthening and resource allocation. ", "purpose and objectives": "This study aimed to develop and pilot a quasi-experimental methodological intervention for measuring system reliability in a primary care setting. The primary objective was to estimate the effect of a structured process mapping intervention on a composite reliability index. ", "methodology": "A quasi-experimental, pre-post intervention design was employed across twelve purposively selected centres. The intervention comprised a formalised process mapping and failure mode identification protocol. System reliability was operationalised as a composite index of appointment adherence, medication availability, and equipment functionality. The primary analysis used a linear mixed-effects model: Y{ij = \0 + \1 Tij + ui +, where ui \ N (0, \²u), with robust standard errors clustered by centre. ", "findings": "The process mapping intervention was associated with a statistically significant increase in the mean composite reliability index (pre-intervention M=0. 65, post-intervention M=0. 78). The adjusted mean difference was 0. 13 (95% CI: 0. 07 to 0. 19, p<0. 01). The greatest improvement was observed in medication availability, which increased by 22 percentage points. ", "conclusion": "The proposed methodological intervention provides a feasible and quantifiable approach for assessing system reliability in resource-constrained primary care environments. The positive association with the reliability index suggests the utility of structured process evaluation. ", "recommendations": "Implement the methodological framework for routine operational audits within primary care networks. Future research should validate the index against longitudinal health outcomes and test the intervention in a randomised controlled trial. ", "key words": "health systems research, operational reliability, quasi-experimental design, primary healthcare, process evaluation, South Africa", "contribution statement":
Thandiwe Nkosi (2026) studied this question.