Methods based on life cycle thinking have been developed to comprehensively assess the impacts (burdens) and benefits of products (goods and services) and business systems to determine qualitative and quantitative environmental, social, and economic indicators across the value chain.
However, an established comprehensive sustainability assessment method for products still needs to be included that coherently integrates all pillars of sustainability. Methods such as Multi-Criteria Decision Analysis (MCDA), outranking models (ELECTRE, PROMETHEE, VIKOR), Multi-Objective Decision Making (MODM), Data Envelopment Analysis (DEA), Product Environmental Footprint (PEF) normalization and weighting, distance to target weighting methods, and monetary weighting methods, addressing this challenge with the aim to both simplifying the decision process and identifying the optimal case out of a set of alternatives based on certain decision criteria (environmental, social and economic), the majority of them providing a single indicator to facilitate decision-making. However, each method has its own methodological complexity and uses different decision criteria, making its application by beginners and practitioners across the academic and SME sectors unpractical. Our research aim is to provide practical decision tree guidance in selecting and applying aggregation methods for LCSA based on the objective of LCSA integration: 1) obtaining (an) aggregated score (s), 2) Only ranking alternatives, or 3) only visualization of the three sustainability dimensions; as well as, some criteria of importance: a) Potential to generate an aggregate score for each of the three sustainability domains or some domains, b) compensatory sustainability, c) potential to use for a single product and d) requirements of semi-quantitative or quantitative inputs, e) comparative analysis among others.
To achieve the main objective, a literature search was conducted via scientific search tools (e.g., web of science) to identify integration methods applied across the sustainability domains, where an initial examination and additional pre-screenings limit the number of relevant papers retained to 23. Based on these literature reviews, a selection of 14 integration methods or sub-procedures leaders in the multiple criteria-based decision aiding were done, which can be categorized into three groups: Group 1 - Integration methods across sustainability domains (for LCSA), Group 2 – Integration methods with a promising visualization approach for LCSA, Group 3 – Other aggregation methods or sub-procedures commonly used within the environmental and social domains. The integration methods selected were analyzed based on the research aim of LCSA integration as well as some criteria of importance (decision criteria). A structured pathway (foundational decision tree guidance) was proposed to easily select the most appropriate integration method for assessing a set of alternatives under multiple criteria or objectives.
