Multi-Criteria Assessment: Integrating Eco-Design and Safe-and-Sustainable-by-Design Frameworks in Sustainable Manufacturing

Sustainability assessment, incorporating environmental, economic, social aspects and gender dimensions, is crucial for sustainable process routes. This is especially critical during the early stages of product design and development. This study applies a Safe and Sustainable by Design (SSbD)–aligned eco-design analysis and LCA methodology to evaluate and improve the sustainability performance of complex geometry parts manufacturing routes. As a case study, the conventional production routes of five use cases are systematically assessed to identify opportunities for sustainability improvement. For each use case, detailed process trees are developed to map material and process flows, enabling a comprehensive life-cycle inventory analysis. The evaluation employs a multi-criteria assessment approach (MCAA) that integrates environmental, economic (including raw material criticality), chemical risk assessment, and gender-responsive social dimensions. These criteria are quantitatively scored using the C-MET-ESG framework (Criticality; Materials, Energy, Toxins; Environment, Social, Gender). The outcomes are synthesised into colour-coded hotspot tables highlighting high or low-impact materials, processes, and social vulnerabilities across the life cycle. Based on an eco-design checklist developed, recommendations are provided, including substituting high-critical alloys with less-critical alternatives, improving material efficiency, and embedding inclusive workplace practices to mitigate gender inequalities. Again, replacing CNC machining and hazardous chemical post-processing steps with laser- and additive manufacturing - Laser Powder Bed Fusion, along with advanced laser-based post-processing techniques. The resulting hazard-aware, socially inclusive, and technically robust framework demonstrates how integrating life cycle in early-stage product design enhances environmental performance, strengthens social responsibility, and improves economic and supply-chain resilience. These outcomes contribute to achieving multiple UN Sustainable Development Goals—particularly SDGs 3, 5, 8, 9, 10, 12, 13, and 15. Furthermore, it provides a transferable MCAA model for sustainable manufacturing in existing and emerging technologies.