A novel Interval Type-2 Fuzzy best-worst method and combined compromise solution for evaluating eco-friendly packaging alternatives

• A systematic and efficient approach to select the best eco-friendly packaging is proposed. • Asymmetric Interval Type-2 Trapezoidal Fuzzy Sets (IT2TFSs) are used to model ambiguous and uncertain data. • Best Worst Method (BWM) and Combined Compromise Solution (CoCoSo) are integrated in an asymmetric IT2TFS setting. • A new consistency ratio is defined for IT2TFS-BWM to check the reliability of IT2TFS comparisons. • A real case study is presented to show the applicability and capability of IT2TFS-BWM-CoCoSo. Increasing consumer goods and products has inspired environmental activists and policymakers to demand eco-friendly packaging from retailers and manufacturers. At the same time, consumer attitudes about sustainable packaging have changed significantly. In response to these changing consumer sentiments, the packaging value chain is changing, and businesses are seeking to use environmentally friendly packaging for their products. However, choosing the best packaging is a significant challenge for decision-makers (DMs) who must consider many uncontrollable and unpredictable environmental factors. This study aims to design a new methodology for assessing engineering and ecological challenges and proposing a practical approach for selecting the best eco-friendly packaging alternative. We propose a novel model that integrates the Best-Worst Method (BWM) and Combined Compromise Solution (CoCoSo) within an asymmetric Interval Type-2 Trapezoidal Fuzzy Set (IT2TFS) setting. The new IT2TFS-BWM-CoCoSo method consists of two phases: determining the optimal weights of the evaluation criteria and ranking the alternatives. The asymmetric IT2TFS is used in both phases to interpret DMs’ fuzzy preferences. A new consistency ratio (CR) is defined to assess the consistency level of DMs’ preference comparisons expressed by asymmetric IT2TFSs. The asymmetric features add flexibility to DMs’ evaluations without weakening their accuracy. The proposed methodology is applied to a real-life case study of a US-based company that produces and ships handmade crystals. Recycled cardboard and paper, biodegradable packaging peanuts, and eco-friendly plastic and recycled plastics are found to be the best eco-friendly packaging alternatives. The case study results demonstrate the applicability and efficacy of the proposed method and its flexibility in solving sustainable packaging selection problems of companies with similar characteristics. At the same time, the technical features of the proposed framework open the way to a wide range of applications for sustainable consumption and production.