Fogg’s model of behavior change says: motivation is whether people want to change, ability is whether people can change, and prompts are stimuli that provoke actual change.

Ajzen’s theory of planned behavior says: attitude is what a person thinks and feels, subjective norms are what that person thinks others believe, and perceived behavioral control is how easy or hard they think it is to change their behavior.

Lockton’s “Design with Intent” tool includes these and many more theories of change with 101 persuasion tactics grouped into eight theoretical “lenses.”

To encourage better behavior with your design, focus on the user experience, make it easy and compelling for the user to act better.

This study examines how co-creation can facilitate the adoption of circular design strategies in product development, including longer-lasting products, repair, refurbishment and recycling. The research was conducted in collaboration with a multinational company producing small household goods. The goal of this research was to explore how the co-creation process can support the implementation of circular design strategies in the product development process. [...]

Nowadays, the circular economy represents a promising strategy for achieving sustainable development through optimising resource efficiency, extending product lifespans, and reducing environmental impacts. Despite the growing interest in circular design practices, companies often face difficulties integrating these principles into their established New Product Development (NPD) processes. This is mainly due to the overwhelming number of available design tools and methods, which are fragmented, challenging to navigate, overlap in functionality, and lack standardisation. This study provides a comprehensive mapping, classification, and analysis of 77 existing circular design tools identified through a systematic literature review and supplementary online searches. The tools were systematically categorised according to format, data type, industry sector, circular strategies, innovation focus, aims, and applicability across the NPD stages. The results indicate a predominance of physical, qualitative, and sector-agnostic tools, emphasising circularity integration within the Discover, Define, and Develop phases of the design process. This structured classification facilitates stakeholder navigation of existing resources, highlighting opportunities for more targeted, industry-specific tool development, consumer-oriented approaches, and the importance of considering Industry 4.0 technologies in circular design practice. Future research could address these gaps by developing customised frameworks, validating tool effectiveness through real industrial applications, and promoting deeper integration of circular design tools within NPD practices and business objectives.

The Cradle to Cradle (C2C) concept takes natural systems as a source of inspiration, striving toward a positive vision where human society and industry regard waste as “food” for new cycles of use, and are powered entirely by renewable energy. Cradle to Cradle is not about efficiency but about effectiveness—waste need not be minimized if it is food for other cycles, providing positive regenerative impacts. However, this is difficult to achieve in practice. The Circular Economy concept elaborates on the Cradle to Cradle model, prioritizing longer product lifetime and recovering whole products over material recovery through recycling.
The Circular Economy also combines ecological thinking with economic thinking, making a business argument for sustainability.
Both concepts have been very influential in shaping the way we think about design for sustainability.

The short lifespans and rapid innovation cycles of electronic products result in the loss of valuable and critical resources (Bakker, Wang, Huisman, & den Hollander, 2014; Baldé et al., 2024). Strategies aimed at extending product lifetimes, such as design for repair, focus on improving the ease of manual disassembly (De Fazio, Bakker, Flipsen, & Balkenende, 2021). However, connections optimized for repairability can hinder the mechanical separation of materials during recycling. This highlights a critical trade-off: improving repairability can often conflict with recyclability, emphasizing the need for balanced design approaches that address both recovery goals. Navigating these trade-offs requires a deeper understanding of how materials and connection types in electronics affect circular strategies. This research aims to investigate tensions between repairability and recyclability by analyzing a diverse set of electronic products and relating the findings to their design architecture. This study seeks to inform design strategies that optimize for both repairability and recyclability, thus prolonging product lifetime while minimizing resource losses at end-of-life.

Product service systems (PSSs) are revenue models where customers pay the company for the service the product provides, not (only) for the physical product itself.
Designing the revenue model along with the product can align economic incentives with environmental impacts, so the company has an incentive to design products for longer lives.
Both the company and the customer can benefit financially from longer‑lived products billed as services.
Not all product service systems are sustainable environmentally or socially, but if properly designed, they can greatly enable the circular economy.

Current circular economy discourse is largely shaped by metaphors similar to the ones used for a linear economy: the machine metaphor, competitive metaphor and the journey metaphor. Metaphors influence patterns of thought, what ideas and solutions are valued (and which are not). Therefore, if a radical economic change is desired, it is important to explore which radically different metaphors could inform this thinking. This study explores the use of the forest as a source domain to enrich circular economy discourse. First, through a qualitative enquiry, intuitive knowledge about a forest is mapped out. Then, circular economy experts were asked to project these insights onto circular economy discourse. The results are presented as practical subdomains that can be applied within design, business and educational contexts. The findings show rich insights related to dealing with wholeness, the importance of relationship, and response to change. The Results Section presents concrete prompts for activating these source domains and applying these as a prompt for ideation. This research contributes to circular economy education by using metaphors derived from nature as a tool for reflection and novel circular economy conceptualisations.