Multi-Year Performance Evaluation and Trend Tracking of Sustainable Suppliers: An Application of a Hybrid Decision Analysis Model

Amid growing global emphasis on sustainability and supply chain transparency, enterprises—particularly in the resource-intensive electronics manufacturing sector—face increasing pressure to integrate sustainable criteria into supplier performance evaluations. This study develops a multi-year supplier assessment framework that enhances conventional evaluation practices by incorporating sustainability-oriented indicators. Building on a real-world case from a publicly listed Taiwanese electronics manufacturer, the proposed model systematically analyzes the annual performance trends of key suppliers. To address expert judgment uncertainty and confidence, this study employs a Z-numbers-based Decision Trial and Evaluation Laboratory (Z-DEMATEL) technique, which integrates Z fuzzy theory to model the interdependencies among evaluation criteria while capturing the inherent ambiguity and subjectivity of expert assessments. The resulting influence weights inform the subsequent application of PROMETHEE-AL (Preference Ranking Organization Method for Enrichment Evaluation based on Aspiration Level), a preference ranking method incorporating aspiration levels, to aggregate supplier performance scores. This dual-method approach allows for the inclusion of ideal target levels in the ranking process, thereby increasing decision relevance and interpretability. The model is applied to historical data spanning multiple years to identify suppliers with stable or improving performance trajectories, while also flagging declining suppliers for managerial intervention. Empirical findings indicate a continued emphasis on traditional criteria such as cost, quality, and delivery, with sustainability-related indicators receiving limited weight—highlighting an opportunity for strategic improvement in the company’s sustainability transition. The proposed integrated Z-DEMATEL and PROMETHEE-AL model not only strengthens the scientific and practical robustness of supplier evaluations but also supports long-term strategic planning and sustainable supplier development. The methodology can be readily adapted for use in other industry settings seeking to balance operational excellence with sustainability goals.