A Quasi-Experimental Evaluation of Power Distribution System Reliability in Uganda: A Methodological Framework for Infrastructure Diagnostics

{ "background": "Power distribution infrastructure in many developing nations faces chronic reliability challenges, yet robust methodological frameworks for its systematic diagnosis are scarce. Existing assessments often lack the rigour to isolate causal factors from observational data.", "purpose and objectives": "This study develops and applies a novel quasi-experimental framework to evaluate the reliability of power-distribution equipment systems. The primary objective is to demonstrate a diagnostic methodology that quantifies failure causality and system performance under operational stresses.", "methodology": "A quasi-experimental design was implemented, comparing failure rates and downtime in treatment and control groups of distribution transformers and feeder lines. The core analysis employs a difference-in-differences model: $Y{it} = \\beta0 + \\beta1 \\text{Treat}i + \\beta2 \\text{Post}t + \\beta3 (\\text{Treat}i \\times \\text{Post}t) + \\epsilon{it}$, where robust standard errors are clustered at the substation level. Field data encompassed load profiles, environmental exposures, and maintenance records.", "findings": "The methodological application revealed that transformers subjected to sustained overloading (≥110% rated capacity) showed a statistically significant increase in failure likelihood. The estimated treatment effect, $\\beta_3$, was 0.15 (95% CI: 0.09, 0.21), indicating a 15-percentage-point rise in the probability of failure relative to the control group. The framework successfully isolated the impact of operational stress from confounding factors like age and vandalism.", "conclusion": "The proposed quasi-experimental framework provides a rigorous, evidence-based tool for infrastructure diagnostics, moving beyond descriptive statistics to causal inference. It proves viable for identifying critical reliability vulnerabilities in power distribution networks.", "recommendations": "Utilities should adopt quasi-experimental diagnostics for targeted asset management. Investment should prioritise load-balancing interventions and condition-based maintenance for assets identified as high-risk by the model.", "key words": "power distribution