Stakeholder-weighted Causal Modelling for Scenario-Based Circularity Assessment in Product Value Chains: A Case of Electrical and Electronic Equipment

Realizing a circular economy in manufacturing requires coordination across value-chain stakeholders and understanding how local design and operational decisions affect system performance. Existing life-cycle engineering approaches rely on isolated indicators and provide limited support for modelling stakeholder interdependencies. This paper proposes a stakeholder-driven assessment method that links actionable circularity indicators to system-level life-cycle performance. The method integrates Weighted Intuitionistic Fuzzy Delphi and DEMATEL to quantify causal dependencies between stakeholder-controlled indicators and value-chain variables embedded into life-cycle sustainability formulas. A ten-year Product-as-a-Service case study shows that stakeholder weighting moderates systemic and cross-value-chain effects that are difficult to capture with conventional lifecycle assessment (LCA) or lifecycle cost (LCC) analyses.