In light of global sustainability challenges today, systemic and transformative innovation is arguably needed for radically reducing anthropogenic environmental impacts. Life cycle thinking is often cited as a powerful framework to achieve this goal. By using existing products as a starting point exploration, life cycle thinking inhibits creativity by too restrictively framing the eco-design problem. Although appropriate for incremental and rule-based eco-design approaches, life cycle thinking can be a factor of design fixation in innovative design contexts. This thesis aimed to understand the fixation effect in eco-design and how it manifests in real-world corporate settings. The fixation effect is a distinguishing element between two regimes of design: rule-based and innovative. Rule-based design operates within known working principles and frames, where fixation on the dominant design is necessary to converge towards a solution. In innovative design, however, fixation is purposely overcome by reframing the problem to imagine new products with new identities, using new working principles. Our first objective was thus to contrast a rule-based eco-design approach, driven by life cycle thinking, and an innovative ecodesign approach, driven by creative methods. This allowed us to apprehend how life cycle thinking might limit a full exploration of the design space. The interdisciplinary and complex nature of creativity implies that it can be affected on three different levels: individually, through the cognitive style and reaction to creative triggers, socially, through the power dynamics between participants in the ideation exercise, and at the organization level, how structures and management styles can affect intrinsic motivation. Our second, third and fourth objectives were respectively to unravel the cognitive, social and organizational factors that also contribute to (de)fixation during eco-design ideation. With research intervention, qualitative methods and a multiple case study approach, two global engineering firms each experienced a series of two carefully designed workshops: one life-cycledriven, and the other creative-methods-driven. With interviews, observations and recordings of the workshop experiences, the case studies were analyzed with design theory and a framework of cognitive, social and organizational creativity to address our objectives. The results show that life cycle thinking alone may hinder creativity, but when paired with cognitive conditions for creativity, favourable social interactions and specific organizational contexts, eco-design fixation can be overcome. Life cycle thinking caused fixation when it was used in its routine organizational context as a well-known and accepted rule-based eco-design tool. When life cycle thinking was new and the participants were more detached from the tool, life cycle thinking subsequently had little political value, and was an expansive trigger for creative ideas. In this context, life cycle thinking effectively allowed the participants to reframe the problem. The use of participatory design was also favourable for eco-design exploration, especially when the interests of all life cycle phases are given agency during the design process, the firm is less likely to remain fixated on its dominant design. The framing effect of an eco-design methodology therefore does not exist independently of its organizational context. This has profound implications for the sustainable innovation community who is often reliant purely on the frames inherent in life cycle approaches to strive for radical innovation for sustainability. Simply evaluating an innovation with life cycle thinking at different stages of its development does not empower sustainability issues to be at the heart of an innovative design inquiry. The sustainability professional needs to become fluent in creativity and innovative design issues if they are to position life cycle thinking as part of the ideation process to imagine sustainable products of the future that radically challenge the status quo.