Life Cycle Sustainability Prioritization Under Hybrid Information: A Generic Framework

Abstract

Life Cycle Sustainability Assessment (LCSA) which usually combines Life Cycle Assessment (LCA), Life Cycle Costing (LCC) and Social Life Cycle Assessment (SLCA) has been recognized as a powerful tool for sustainability assessment. However, it is still difficult for the decision-makers to select the most sustainable alternative after LCSA, because there are usually various alternative options and various conflict evaluation criteria in the selection process. Moreover, the users usually have to face various uncertainties and some qualitative criteria. It is difficult or even impossible to determine the data with respect to some criteria or use crisp numbers to describe the alternatives with respect to some criteria due to uncertainties and the lack of information. One of the most typical examples is the selection of the most sustainable process for sewage sludge treatment among numerous alternatives. This study aims at developing a multi-actor multi-criteria decision analysis framework for sustainability assessment and prioritization of the alternative processes under hybrid information. Multi-actor weighting method was developed for determining the weights of the evaluation criteria. It allows different groups of decision-makers to participate in the weighting process, and this method can successfully solve the problems of the ambiguity and hesitations existing in the judgments of the stakeholders. Multi-actor multi-criteria decision analysis method under hybrid information was proposed to prioritize the alternative processes. Three alternative processes for waste management were studied by the proposed method, and the results reveal that the proposed method can facilitate the decision-makers to select the most sustainable process among a variety of alternatives. Sensitivity analysis was also carried to investigate the effects of the weights on the final sustainability ranking of these three alternatives (The work was financially supported by the Hong Kong Research Grants Council for Early Career Scheme (Grant No. 25208118)).

Keywords: life cycle sustainability assessment; multi-criteria decision making; sustainability; weighting method