Sustainable supplier selection for water environment treatment public-private partnership projects

Sustainable supplier selection is critical to the operation of water environment treatment Public-Private Partnership (PPP) projects. This paper considered the sustainability of suppliers and established a sustainable supplier selection indicator system using five aspects. This paper introduces the Shapley value method to modify the index weights determined by the analytic hierarchy process (AHP) in order to overcome differences in expert cognition. The Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) decision model based on interval-valued intuitionistic fuzzy sets (IVIFSs) was constructed to select sustainable suppliers for water environmental treatment PPP projects. The decision-making model was used to select a supplier for a case, and the result of that selection was compared and verified with different decision-making methods. The use of IVIFSs in the decision-making process can reduce the ambiguity and uncertainty of expert judgment. The results show that the supplier's own sustainability has an important impact on the sustainable development of the project. Moreover, the supplier's sustainable financial capabilities and sustainable technology solutions are key factors that need to be considered when choosing a sustainable supplier. This paper conducts comparative verification and sensitivity analysis to verify the effectiveness of the method. This article considers the sustainability of suppliers, which provides a new research direction for improving the sustainability of PPP projects. The index system and decision-making methods in this article can help governments in developing countries select suitable water environment treatment suppliers and improve the sustainability of public services.