Addressing heterogeneity sources in manufacturing sustainability assessment using the system design view

Assessing manufacturing sustainability has become a task of paramount importance to date for the decisional impact over the whole product or process life cycle. The consistency of the sustainability assessment results derives from several practitioner's choices and assumptions, depending on materials, the technological processes as well as the geographical context, that may be sources of heterogeneity. Addressing the sources of heterogeneity in sustainability assessment deriving from data contexts, procedural decision-making methods, measurement procedures is critical, provided that all existing methodologies, such as Life Cycle Assessment, Exergy Analysis and methods derived from their combinations, leave an important role to the subjective judgment of the practitioner. Heterogeneity is thus related to the possible different perspectives in drawing decisions, which may, for instance, reflect into the selection of dissimilar inventorying for the impact evaluation as well as in the selection of the most suitable impact category: the effect is the uncertainty in the final results. Heterogeneity issue can be attributed to multiple dimensions, such as data sources, indicators and subjective perspectives. In this paper, the problem of facing the sources of heterogeneity in sustainability assessment is discussed by endeavoring the system design view as a kind of guideline to implement the Exergy-based Analysis within the Life Cycle Thinking. The Life Cycle Assessment and Exergetic Analysis approach is carried out not to improve the methods themselves, but to revisit the entire design process, to improve it, with the aim of driving the decision of the practitioner, to make the results of the assessment more comparable, regardless of their subjective choices. An industrial case study is taken as a reference to prove the approach proposed and to highlight gaps that have not yet been filled. (C) 2022 CIRP.