A General Framework for Sustainability Assessment of Manufacturing Processes

Abstract

The manufacturing sector has a major impact on the three sustainability dimensions represented by social, economic, and environmental aspects. Most of the work on sustainability assessment in the field of manufacturing is conducted at the product level or for specific processes; mainly machining with a limited number of indicators that do not capture all three dimensions of sustainability. The aim of this work is to develop a new systematic and comprehensive framework for the sustainability assessment of manufacturing processes that covers the three sustainability dimensions. Guidelines to select and quantify the relevant indicators, convert the quantified weighted indicators into dimensionless quantities, and rank the alternatives based on the aggregated scores are presented. The proposed framework combines objective and subjective weighting methods to reduce the uncertainty associated with subjective weighting. It also captures the interaction among different indicators by utilizing multi-criteria decision making methods instead of the traditional statistical methods. Sensitivity analysis is proposed to ensure the reliability and robustness of the aggregated results (final scores). A case study is carried out by applying the proposed framework to evaluate the sustainability level of four welding processes, which are Friction Stir Welding (FSW), Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW) and Shielded Metal Arc Welding (SMAW). The four processes are used to weld aluminum 5083 plates with a thickness of 5 mm. Physical performance of the welded plates is considered as a fourth sustainability dimension to assess the quality of the welded parts. The assessment is carried out using three multi-criteria decision making methods, which are the TOPSIS, GRA and COPRAS. The results obtained from the assessment reflect that the FSW welding is the most sustainable welding process for this case with an overall sustainability score of 0.611 based on TOPSIS method, 0.753 based on GRA, and 0.317 based on the COPRAS method.