Identifying and prioritizing key factors to sustainable supply chain in the steel sector: a multi-method approach

Purpose The research aim was to work on the discrepancies and ambiguities that have emerged with the application of individual multi-criteria decision-making (MCDM) methods in the determination of key factors in sustainable supply chain management. It aims at improving reliability of the decision-making process by suggesting an aggregation procedure to combine the various decision outcomes. Design/methodology/approach Several decision methods, including analytic hierarchy process (AHP), best-worst method (BWM) and fuzzy AHP, were employed to assess and rank the factors for achieving sustainability in steel supply chain. These methods produce different ranking since they make different assumptions, have different preference structures and different data processing mechanisms. To counter this, we made use of the half quadratic (HQ) theory to enable us to compile these rankings. HQ-based method combines varying expert estimation and methodological opinion into single final ranking. Findings The HQ-based aggregation can improve consistency and sturdiness of the final ranking; it eliminates the difference in approach. This method facilitates stable and consistent decision-making and helps in consistent strategic planning and policy making of sustainable supply chain management. Originality/value The novelty of this study lies in the use of HQ theory in aggregating the ranking based on two or more decision-making methods. It shows how this method is effective in eliminating the uncertainty that comes with single method methods as well as reveals how aggregating is important in enhancing the validity of MCDM in the use of sustainability in analysing a supply chain.