Abstract:
The objectives of the study are to find the optimal solution that minimizes transportation cost
by choosing economical route for transportation the pipes for water supply from different stores
to the sites and to find the efficient route that make optimal transportation schedule in Sri
Lanka. The transportation data related to length of pipe required for eleven site locations,
availability of pipes at stores, number of truck loads which need to be transported, required
truck load for sites and available truck loads at stores and transport cost per truck load were
calculated from the national water supply and drainage board report in 2020. The data was
modelled as mathematical form using linear programming of transportation type and
represented as transportation tableau which was done by Excel Solver to generate its initial
basic feasible solution and optimal solution as well as for further improvement like sensitivity
analysis in the study. The experimental results show that, the optimum solution of the
transportation problem is Rs 79,363/= and at the real situation, number of trucks hired should
be an integer value. Based on this aspect, actual minimum total cost for transport is Rs
91,175/=. Further, based on the solver solution material transport arrangement, most cost
effective route of transporting materials from national water supply and drainage stores to the
relevant sites also were identified. In addition to the above results, sensitivity analysis including
reduced cost, allowable increase and decrease in current coefficient and constraints as well as
shadow prices also estimated in the study. The findings of the may useful to the managers and
engineers who involve on water supply and drainage to provide the effective water distribution
systems to the various locations at a minimum transportation cost in the country.
