Decision support system for optimisation and expansion of water supply systems in developing countries

December 2, 2025

Access to safe drinking water remains a challenge in developing countries due to rapid urbanisation, financial constraints, and institutional weaknesses. In these settings, water supply systems are frequently characterised by the coexistence of formal utilities and informal service providers. Addressing this complexity requires decision-support approaches capable of analysing piped and non-piped service modalities in an integrated framework. This dissertation introduces the DSS.WS@DC model (Decision Support System for Optimisation and Expansion of Water Supply Systems in Developing Countries), developed to support inclusive and technically feasible strategies for water distribution. Built in Microsoft Excel with Visual Basic for Applications, the model guides decision-making through three phases: (1) characterisation of the existing water supply system; (2) optimisation of abstraction and treatment, and generation of alternatives; (3) evaluation and ranking of alternatives using a multi-criteria framework that integrates technical, social, economic, and environmental factors. The model was applied to Tombwa, Angola, a coastal city with documented water distribution gaps. Alternatives were created and ranked based on expert-defined criteria weights, showing potential to improve service coverage. The sensitivity analysis confirmed result robustness under varying stakeholder priorities. Moreover, a second model application demonstrated that the DSS.WS@DC serves not only as an open-ended system optimisation/expansion exercise for strategic planning, but also to support decision-making based on specific objectives, serving as an evaluation framework for targeted investment options. Overall, the research proposes a practical methodology for planning water supply in low-resource settings, promoting inclusive development and informed decision-making.

Authors in the community:

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  C

  Carolina Frederico Simões Gonçalves

  ist186827

Supervisors of this institution:

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  F

  Filipa Maria Santos Ferreira

  ist14202

civil-engineering - Civil engineering

por - Portuguese

Instituto Superior Técnico