Aggregation of indicators in the context of Life Cycle Sustainability Assessment

In this study need for new approaches for aggregating sustainability indicators in the context of Life Cycle Sustainability Assessment (LCSA) has been identified. LCSA present a challenge to provide decision support as the... [ view full abstract ]

In this study need for new approaches for aggregating sustainability indicators in the context of Life Cycle Sustainability Assessment (LCSA) has been identified. LCSA present a challenge to provide decision support as the assessment leads to quantification of performance of system from environmental, economic and social perspectives. This makes it evident that conventional way of aggregating indicators by simple weighted sum method will not be able to provide rational decision support to policy makers.
This study evaluate this hypothesis by applying a systematic approach and investigates the prevailing practice of obtaining single scores in Life Cycle Assessment (LCA). Potential lacunas in impact assessment methodology related to the results of aggregation into endpoints and single scores are also presented.
Three main problems related to the single score calculation approach have been found. The prevailing ReCiPe single score calculation method does not account for either the effect of so-called dominating alternatives (i.e., alternatives having high values across all endpoints) or the interdependency of the indicators being aggregated. Major limitation of the present single score calculation method identified was insensitivity towards the weighting schemes chosen by LCA the practice i.e. presently used for obtaining single scores, is not capable of accounting for the effect of weighing schemes and thus cannot realistically represent stakeholders’ perspectives.
Finally, we propose a distance-based Multiple Attribute Decision Making (MADM) method for use in obtaining single scores. This method was found to be more suitable, as it takes into account the weighing schemes and types of indicators in the process of estimating single scores. The new single score calculation method proposed here is considered ideal for environmental decision-making problems in the context of Life Cycle Sustainability Assessment (LCSA). Thus, it is also ideal for situations in which more complex decision-making situations will emerge by combining LCA indicators (midpoints or endpoints) with other indicators representing the performance of a system from economic and social perspectives.