A Multi-Criteria Decision-Making Model to Evaluate Sustainable Product Designs Based on the Principles of Design for Sustainability and Fuzzy Analytic Hierarchy Process

The exponential and adverse increase in global conditions like climate change, ocean acidification and aerosol loading stresses the urgency to achieve sustainable development in all global activities, including manufacturing. Despite the attempts of developing disparate approaches and concepts at different scales of economies, the global issues are still worsening. As a consequence, United Nations Environment Programme (UNEP) has introduced the concept of Design for Sustainability (DfS) to evaluate the sustainability aspects of product designs, acknowledging the importance of developing sustainable products (and services). Even though the DfS approach has been recognised as an appropriate base to establish a sustainable global economy, the scope of the assessment still requires further research, specifically with the social impacts assessment. Hence, in this study, we propose a multi-criteria decision support system based on the DfS principles, including an exhaustive set of criteria referred in the Social Life Cycle Assessment framework for the purpose of evaluating three chosen sanitation system designs. We applied the Fuzzy Analytic Hierarchy Process to solve the proposed model. Additionally, a sensitivity analysis was performed to understand the effects of the chosen priority weights. The analysis shows that the sanitation system design choice is heavily influenced depending on whether the high importance the packaging and logistics phase or the usage phase, emphasising the need for a comprehensive life-cycle analysis. The research reported in this paper is a step toward realising the targets of DfS at a practice level by simultaneously building on the original proposals and using them to solve real word design selection problems.