Proposition and Application of Multi-Criteria Analysis With Fuzzy Logic Approach and Consequential Life Cycle Assessment to Support Decision Making

Abstract

Purpose Use the consequential life cycle assessment (cLCA) tool to support decision-makers in product and service sustainability analyses. Methods Approach using a multicriteria fuzzy controller (MFC) associated with the cLCA to assist in the sustainability assessment, including different perspectives (environmental, exergetic, and economic), allowing more objectivity and confidence in interpreting results. The case used in this study to test the purpose uses a cradle-to-grave approach with a system expansion boundary (avoided burdens) of transporting one ton of cargo by one kilometer, with diesel B, using four ReCipe Midpoint categories (H) and the Cumulative Exergy Demand – CExD in the impact assessment. Three representative variables were chosen to test the integrated approach, two LCIA categories (CC and CExD) and an economic variable (Price). Results This work presented an approach that integrates cLCA and Fuzzy Logic, solving the limitations mentioned and providing a decision-making tool that can receive inputs from any Triple Bottom Line dimension (environmental, social, and economic) and generate objective results. When used autonomously, the cLCIA presents results with trade-offs, categories with positive (CC, FE, and ALO), negative (CExD), or neutral impacts (NLT). When combined with Fuzzy Logic, the results bring surfaces, and response areas that allow decision-makers to visualize the limits and trends of the best scenarios, facilitating consensus and managing conflicts. Conclusions The association of fuzzy controller LCA tools enabled more direct and objective results and findings to support decision-making, integrating different sustainability perspectives. Specifically, in the case study of biofuels, the approach allows decision-makers to assess future scenarios about their composition to reconcile compliance with international environmental agreements with local socio-economic needs.