Material Selection Method Based on Health, Reliability and Cost for Water Supply Pipe

<ns5:p>Background This study develops an enhanced decision-making framework to support the selection of suitable non-metallic and metallic materials for water supply pipes (WSPs), with an emphasis on health safety, reliability and cost efficiency. The originality of the research lies in integrating three interdisciplinary domains—engineering, public health, and economics—within a unified material selection (MS) process. Based on user requirements and expert opinions, three key evaluation criteria for WSPs were identified: (i) safety and reliability, (ii) cost, and (iii) health and cleanliness. Methods The study addresses two main challenges. First, overcoming the difficulty of constructing a consistent pairwise comparison matrix in the Analytic Hierarchy Process (AHP) Second, selecting an appropriate pipe material that simultaneously satisfies engineering performance, health considerations, and economic feasibility. To address the first issue, Yang’s improved paired-comparison approach was adopted using a newly designed questionnaire. Five commonly used pipe materials were evaluated: thin-walled copper, PVC-lined galvanized steel, PP-R, PVC-U, and thin-walled stainless steel. Their key characteristics were analyzed, and the materials were quantitatively optimized using the AHP method with a nine-point comparison scale. Results The results indicate that PP-R pipes achieved the highest overall priority weight (0.695), making them the most suitable option for water supply systems under the selected criteria. Sensitivity analysis further confirmed the robustness of the improved AHP model, as the ranking of PP-R (M4) remained stable under 10–20% variations in the weights of safety and reliability, health, and cost criteria. Conclusions These findings are consistent with recent improved AHP and multi-criteria decision-making studies on pipe material selection. The proposed framework provides a practical guide for decision-makers in selecting appropriate materials for water supply systems.</ns5:p>