The attention to sustainability impacts arising during the lifecycle of products is growing as industry wants to increase its contribution to a sustainable society. To do so, companies must find ways to navigate the complexity of the needs within the socio-ecological system in which they operate. In engineering design projects, the interpretation of needs into requirements is essential, as they represent the collective understanding of the design problem to be solved. Ideally, requirements are possible to verify and validate, which makes it challenging for industry to integrate socio-ecological considerations, often based on qualitative models, into requirements. Sustainability then tends not to be prioritized in trade-offs with traditionally identified requirements for engineering design.

A qualitative research approach within design research methodology framed a sequence of studies guided by the research question ‘How can requirements be utilized to support Sustainable Product Development?’ First, a research gap was identified from a literature review which indicated a lack of socio-ecological systems contextualization in the identification, as well as the traceability of sustainability criteria to integrate into requirements. Secondly, a conceptual model was established for how management of requirements can be improved to facilitate traceability, as well as how contextual socio-ecological systems perspective can be introduced in the selection, of sustainability criteria for engineering design projects. For this purpose, the results from a multiple-case study based on semi-structured interviews with seven design and manufacturing companies was triangulated with findings of an in-depth literature analysis. Five key elements of management of sustainability in requirements were proposed in a profile model corresponding to different levels of sustainability maturity. A third study explored, based on literature and prototype causal loop diagramming, the potential of a group model building approach to enhance contextual understanding of strategically identified, i.e., company-tailored, sustainability criteria in relation to traditional requirements in early phases of the product innovation process. A final study investigated how a strategic sustainability perspective can be integrated with engineering design methods and value modelling to create a decision support for concept selection.

The studies together indicate that key constituents of good requirements, traceability and systems contextualization, can be achieved also for socio-ecological sustainability considerations. This requires organizational commitment and will be reflected in the design of the operational management system for their product innovation process. Following the proposed five key elements of sustainability integration in requirements, a company is expected to increase the organizational sustainability maturity, and hence its capability to contribute to a sustainability transition. This research also shows that there is a gap in current methods and tools for enhanced socio-ecological systems contextualization. The two last studies of this thesis give promising approaches of tools and methods to be further developed and analyzed, namely group model building, system analysis and value modelling.