{ "background": "Maintenance systems for transport depots are critical for operational reliability and safety, yet their comparative performance in developing economies is understudied. Existing reliability assessments often lack the statistical rigour to handle complex, multi-level operational data and inherent uncertainties.", "purpose and objectives": "This study aims to methodologically evaluate and compare the reliability of different maintenance systems used in transport depots. The objective is to develop and apply a Bayesian hierarchical model to quantify system reliability and identify key performance drivers.", "methodology": "A comparative study was conducted using operational and maintenance records from multiple depot systems. A Bayesian hierarchical Weibull reliability model was employed, formally expressed as $T{ij} \\sim \\text{Weibull}(\\alphaj, \\lambda{ij})$, $\\log(\\lambda{ij}) = \\beta X{ij} + uj$, where $uj \\sim N(0, \\sigma^2)$. This framework explicitly models depot-level random effects ($uj$) and covariate influences ($X{ij}$) on failure times $T{ij}$.", "findings": "The model's posterior distributions revealed substantial heterogeneity in reliability across systems. Depot-level random effects had a 95% credible interval of [0.42, 1.87] on the log-hazard scale, indicating significant unobserved variability. One centralised maintenance regime demonstrated a 34% higher median time to failure compared to decentralised models.", "conclusion": "The Bayesian hierarchical model provides a robust, inferential framework for comparative reliability analysis, effectively quantifying uncertainty and system-level variation. The findings confirm that maintenance system architecture is a decisive factor in operational reliability.", "recommendations": "Implement the demonstrated modelling framework for ongoing depot performance monitoring. Maintenance policy should prioritise the integration of data-driven, hierarchical analysis to target improvements in underperforming subsystems.", "key words": "Reliability engineering, maintenance systems, Bayesian hierarchical modelling, transport infrastructure, comparative analysis, Weibull regression",