Water treatment chemical supply chain disruption risk assessment and mitigation strategy ranking using BWM-VIKOR.

Chemical supply disruptions can compromise compliance with water treatment regulations and service continuity. This study proposes an integrated multi-criteria decision-making framework that combines the Best–Worst Method (BWM) and VIKOR to prioritize mitigation strategies for water treatment chemical supply chain disruptions. A case application at Shanghai’s Yangshupu Water Plant demonstrates the approach. BWM-based weighting shows that compliance/public health (0.26) and service continuity (0.18) dominate decision priorities (44% combined), followed by recoverability/flexibility (0.16) and supply vulnerability (0.14). Using these weights, VIKOR ranks mitigation alternatives and identifies a compromise set. Under baseline conditions ([Formula: see text]), dual sourcing and supplier prequalification achieve the best compromise performance ([Formula: see text], [Formula: see text]), while safety stock and reorder redesign minimize worst-case regret [Formula: see text]; the acceptable advantage condition is not satisfied ([Formula: see text]), leading to a compromise set [Formula: see text]. Sensitivity and scenario tests confirm that the shortlist is robust, with safety stock becoming top-ranked under prolonged logistics disruption and QA/QC strengthening rising under quality failures. The proposed framework provides transparent, defensible support for utility resilience planning.