Improvement of Maintenance Management System to Enhance Availability Performance of Water Distribution Systems: A Case Study of Mivumoni, Dar es Salaam Region

This study presents the improvement of a maintenance management system designed to enhance the availability performance of water distribution systems in the Mivumoni region of Dar es Salaam, Tanzania. The research addresses critical challenges in water infrastructure maintenance where reactive maintenance practices have led to system availability of only 65-70%, significantly below the international benchmark of 95% for urban water systems. Using a mixed-method approach with 91 participants across different technical and managerial levels at DAWASA, the study employed the Relative Importance Index (RII) to identify and prioritise factors affecting maintenance practices. Technical factors emerged as most significant, with equipment condition (RII = 0.936), spare parts availability (RII = 0.932), and infrastructure age (RII = 0.919) ranking highest. Managerial factors showed varying significance, with budget allocation (RII = 0.925) and quality control (RII = 0.837) proving crucial. A regression model was developed showing strong predictive capability (R = 0.983, R² = 0.840) for availability performance. The model validation through monthly performance data revealed an overall average availability of 85.52%, with technical infrastructure age showing the strongest negative impact (β = -0.99), while spare parts availability (β = 0.43) and technology level (β = 0.22) demonstrated positive influences. The analysis revealed predominant reliance on reactive (27.5%) and run-to-failure (27.5%) maintenance strategies. The research concludes that an integrated maintenance management system combining proactive strategies, enhanced monitoring capabilities, and improved resource allocation methods is essential for optimising system availability performance and achieving sustainable water distribution in rapidly urbanising regions