Selecting the Proper Type of Pipe for Less Populated Area Water Distribution Networks Using OWA-TOPSIS Considering Group Consensus

The right water pipe selection would save the cost and minimize the wasted water in the water conveyance and distribution systems. The aim of this study is to determine the proper pipe for water networks in less populated areas. Villages of East Azerbaijan, Iran is studied in detail as the case study to this research. To evaluate different types of the pipes, 22 effective criteria are initially proposed through questioning nineteen experts. The degrees of consensus of decision-makers on the weights of these criteria are calculated by a rigid consensus way; standard deviation method. With the help of a rigid consensus degree, 8 of the criteria with higher consensus were then selected. The final choice for pipe type among the four types of Polyethylene, Steel, Ductile Cast Iron, and PVC is then made based on the rigid method using TOPSIS. Again, to check the consensus on criteria using soft methods, a questionnaire is designed. Seven experts, who worked on the previous part, evaluated the criteria in a pairwise approach. The weights for the eight criteria have been calculated with the Orderd Weighted Averaging method (OWA) and finally the alternatives are ranked with TOPSIS method. Using GFDM software a more detailed sensitivity analysis has been also performed. Finally the polyethylene pipe is recommended as a most robust and effective option.