Decision of water supply line under uncertainty

Alternatives that are generally considered as a water supply line for conveying the collected and treated water from the source to community are studied. To evaluate and rank these alternatives, several indicators are then made based on the technical feasibility of methods for constructing a water supply pipeline, the safety of hydraulic pressure or velocity, and the reasonableness of the cost required. However, assessing technical feasibility, safety and cost contains elements of uncertainty due to a lack of available information, the randomness of future situations, and the incomplete knowledge of the expert. In this study, a methodology using fuzzy sets is presented to assist decision makers in evaluating various water supply lines with uncertain information, in order to decide a proper line. The methodology allows decision makers to characterize associated uncertainty and incorporate it directly into the decision-making process so decisions can be made that are more appropriate and realistic than those made without taking uncertainty into account.