For product designers, the world has traditionally been one of resource
abundance. Introducing them to a resource-constrained world thus
requires new design strategies. This chapter explores how embedding
circular economy principles into design practice and education could
help product designers take critical material problems into account. We
introduce four product design strategies that address materials criticality:
(1) avoiding and (2) minimizing the use of critical materials, (3)
designing products for prolonged use and reuse, and (4) designing
products for recycling. The ‘circular’ strategies (3) and (4) are
elaborated, as these sit most firmly within the remit of product design.
This leads to a typology of circular product design that redefines product
and material lifetime in terms of obsolescence, and introduces a range of
approaches to resist, postpone or reverse product and material
obsolescence. The typology establishes the basis for the field of circular
product design, bringing together design approaches that were until this
date unconnected and paving the way for the development of detailed
design methods.@en

This thesis argues that in order to increase the likelihood that product lifetime extension in a circular economy will be successful from both an environmental and an economic perspective, industrial designers need to be able to control not only the spatial dimension (materialization and geometry) of products, but also their temporal dimension. This temporal dimension is related to the number and duration of product use cycles and the duration of the total product lifetime. To enable industrial designers to capture this temporal dimension, the thesis presents:
• a new design methodology: design for managing obsolescence;
• five new design methods and two typologies in support of managing obsolescence;
• insight into (the factors determining) how and when to best apply these methods;
• insight into where and in collaboration with whom to apply these methods in the product innovation process.@en

In a circular economy (CE), the economic and environmental value of materials is preserved for as long as possible by keeping them in the economic system, either by lengthening the life of the products formed from them or by looping them back in the system to be reused. The notion of waste no longer exists in a CE, because products and materials are, in principle, reused and cycled indefinitely. Taking this description as a starting point, the article asks which guiding principles, design strategies, and methods are required for circular product design and to what extent these differ from the principles, strategies, and methods of eco-design. The article argues that there is a fundamental distinction to be made between eco-design and circular product design and proceeds to develop, based on an extensive literature review, a set of new concepts and definitions, starting from a redefinition of product lifetime and introducing new terms such as presource and recovery horizon. The article then takes Walter Stahel's Inertia Principle as the guiding principle in circular product design and develops a typology of approaches for Design for Product Integrity, with a focus on tangible durable consumer products. The newly developed typology contributes to a deeper understanding of the CE as a concept and informs the discussion on the role of product design in a CE.

@en

Very often, a circular economy is equated with a recycling economy. Implementing a full-scale recycling economy may seem challenging enough, but in this paper we argue that the real challenge of the circular economy lies in the exploitation of the so-called ‘inner loops’, where a product’s lifetime is extended through for instance repair, refurbishment or remanufacture. The inner loops enable the capture of a product’s embedded value over time, in a systemic way, over and over again. This paper addresses the question which business model archetypes best enable product lifetime extension, in a circular economy. Five business model archetypes are presented. Four of these are relatively well-known and have to some extent been described in the literature. These include the ‘access’ and ‘performance’ business models. The fifth, Gap Exploiter, however has a special status: it concerns businesses that are built around extending the lifetime of products from other firms. They are called Gap Exploiters because they exploit product lifetime value gaps. Familiar examples are companies that refurbish used phones and computers. They generally procure their resources at no or very low exchange value, in order to add substantial perceived use value. The paper explores the meaning and value of Gap Exploiters in a Circular Economy.@en