Normalization and weighting methods for precise and standardized sustainability assessment: recent practices in manufacturing

Abstract

To address the challenges of sustainable manufacturing, precise, transparent and standardized sustainability assessment is essential. In this regard, normalization and weighting approaches are key tools to improve the precision, transparency and robustness of sustainability assessment efforts. However, mostly, the available literature on sustainability assessment discusses less about normalization and weighting. Moreover, previously, most of the related sustainability assessment and review studies were based on normalization and weighting for life cycle assessment (environmental dimension) only. Thus, this paper aims to present the recent status quo of normalization and weighting practices for sustainability assessment in manufacturing. Unlike previous review studies, this paper includes all three dimensions of sustainability (environment, economy and society). In order to achieve this objective, recent sustainability assessment studies (published in last 10 years) were reviewed and analyzed, from normalization and weighting viewpoints. The results showed that a majority of the reviewed studies which considered all three dimensions of sustainability were based on internal normalization. In contrast, the environmental assessment based studies were mostly grounded on external normalization. In addition, most of the reviewed studies considering all three dimensions of sustainability were concerned with normalization of input and/or output indicators, whereas environment based studies were mostly normalized for impact indicators. For weighting purposes, the analytic hierarchy process method was used most commonly, whereas the Delphi method and others were less frequently employed. Overall, more future work is required to increase awareness and usage of normalization and weighting methods for sustainability assessment in manufacturing.