A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of
Master’s in Mathematical and Computer Sciences and Engineering of the Nelson
Mandela African Institution of Science and Technology
Water loss in water distribution systems (WDS) is a serious problem in developing countries.
A lot of water is lost on its way from the sources before reaching the consumers due to leakage,
illegal use, and theft of infrastructures among others. The effect of water loss in the WDS
includes reduction of revenue, water shortage, disruption of water quality, and inflation of
operation and maintenance cost of the water authorities. The control of water loss in the WDS
is closely dependent on the commitment of the decision-makers, the strategies used and budget
set for water loss management (WLM).
This study presents a combined model of Multi-Criteria Decision Making (MCDM) and Integer
Linear Programming (ILP) methods which may help decision-makers to prioritise and select
the best strategies for WLM. The MCDM family methods; the MAVT, SMARTER, SAW, and
COPRAS were used to evaluate and prioritize the strategies, while ILP was used to select the
best strategies. Additionally, the study compared the SAW and COPRAS methods in
prioritising and selecting the strategies. The data used were collected at MUWSA.
The results show that the COPRAS and SAW methods rank the given alternatives differently
while when integrated with the ILP technique, the formulated models select the same portfolios
of alternatives. Thirteen alternatives which cost 97% of the total budgets set for WLM were
selected. Furthermore, the ILP models showed robustness in selecting the portfolio of
alternatives as they select the same alternatives despite the ranking of alternatives and change
of weights of evaluation criteria.
Finally, the study proposed the decision model framework which can be used by decisionmakers
to
evaluate
and
select
the
best
strategies
for
WLM
in
WDS.