African Metallurgy Journal (Engineering/Materials focus) | 16 February 2009
Power-Distribution Equipment Reliability in Tanzanian Mines: A Multilevel Regression Analysis
K, a, s, i, n, i, M, w, a, l, i, m, u, ,, M, w, a, m, a, l, a, C, h, i, t, u, u, d, o
Abstract
This study examines the reliability of power-distribution equipment (PDE) in Tanzanian mines, focusing on identifying factors that influence system performance and maintenance needs. A multilevel regression model was employed to analyse data collected from multiple mines over two years, accounting for both fixed effects (mine-specific characteristics) and random effects (variation within mines). The analysis revealed a significant interaction effect between temperature and humidity on PDE failure rates, with higher failure rates observed in environments exceeding 30% relative humidity. The multilevel regression model provides insights into the factors affecting PDE reliability, offering targeted recommendations for maintenance scheduling to enhance equipment longevity. Based on findings, a proactive maintenance strategy should be implemented, with scheduled inspections during high-risk periods identified by environmental conditions. The maintenance outcome was modelled as $Y<em>{it}=\beta</em>0+\beta<em>1X</em>{it}+u<em>i+\varepsilon</em>{it}$, with robustness checked using heteroskedasticity-consistent errors.