1. Introduction
The concept of the circular economy is a vision for how the global economy can operate in a way that is regenerative and restorative by intention and design [
1]. It is a collection of a number of different ideas, brought together as a means of reframing the debate around resource use and waste [
2]. Based on a ‘systems thinking’ approach, the aim is to design out waste and other negative externalities, preserve and enhance natural capital and circulate products, components and materials at their highest level of utility and value [
3,
4].
In addition to the environmental arguments, there is also a strong business rationale for switching to a circular economy. This is in part built on a number of inherent problems in the linear ‘take-make-dispose’ model of production, including supply and price risks from the extraction of virgin materials, to growing regulatory pressures [
5,
6]. There are also potential opportunities for businesses to create more value through moving to a circular model, such as through circulating assets for longer and intensifying product use [
7,
8].
Transitioning to a circular economy relies, in part, on businesses incorporating circular economy principles into their business models [
9], thereby radically rethinking how they operate [
10]. These principles can be implemented across a number of stages of the product value chain, such as sourcing circular supplies or recovering used resources [
11]. Product Service Systems (PSS) are an example of a circular business model which are based on a customer value proposition made up of a mixture of products and services [
12]. The ideas being that by shifting profit creation away from high volume sales and towards providing services, PSS create economic incentives to slow resources and materials flowing through the economy [
10,
12].
Building on the work of Stahel [
13,
14] and McDonough & Braungart [
15], Bocken et al. [
10] outline two fundamental strategies for designing products and business models for a circular economy; slowing of resource loops and closing resource loops. Slowing of resource loops involves increasing the utilisation of products, either through extending product lifetime (through durable design, design for maintenance etc.), as well as increasing utilisation through sharing schemes or PSS. Closing resource loops relates to ensuring that materials can be recycled in a closed-loop fashion at the end of use [
10].
Examining these two fundamental design objectives described by Bocken et al. [
10], it can be argued that customer behaviour can have an influence over both. When looking at the role of extending product longevity, Cox et al. [
16] found that product lifetime depended as much on human factors as it did on functional product durability. The view that users of products drive product lifetimes is supported by many authors (including den Hollander et al. [
17]; Van den Berg & Bakker [
18]; Mugge et al. [
19]). In the context of PSS for a circular economy, Tukker [
12] has suggested that people treat products that they do not own with less care, in some cases leading to higher environmental impacts. Customers can also prevent the closing of material loops or cause products to be under-utilised; ‘hibernating’ their old products by storing them away after they no longer want them [
20] or disposing of them in a way which means their material and product value is lost [
21]. Bakker et al. [
22] (p. 31), summarised the guiding principles of the linear model of production as ‘design something, manufacture it as the lowest possible cost, sell it at the highest possible price and forget about it as soon as feasibly possible.’. These objectives change when viewed from the perspective of a circular business model. Here, there is an increased interest in what happens to products once they have left the manufacturer or retailer and a greater focus on getting products or materials back after use so that they can be re-used, remanufactured or recycled. An interesting part of this change, is that with business to consumer (B2C) models, the customer and their behaviour become an integral part of the process. The user of a product and their behaviour can have a significant influence on the overall flow of products, components and materials.
Accenture have stated that the ability of a business to engage and incentivise customers to use and dispose of products correctly is one of the key capabilities of a leading circular company [
11]. There is therefore a human element to the circular economy, which is acknowledged, but despite the importance of the role of the ‘owner’ or ‘user’ of a product, their part in the circular economy has not yet been clearly described. It has been suggested by a number of authors that designers can play a role in moving towards a circular economy, through their ability to understand and influence business and consumer behaviour [
23,
24,
25]. Despite this, limited work has gone into equipping designers with the skills needed to understand or encourage these desired behaviours. Therefore, to help to address this gap in the literature, the aim of this paper is twofold:
to define exactly what user behaviour, if any, is required to enable a transition to a more circular economy;
to create a framework for designing products and services to encourage desired circular behaviours.
To achieve these aims, first, an extensive review of the relevant literature was conducted to identify user behaviours and design strategies. These were built on by a case study analysis of circular business models for durable consumer goods. Finally, interviews were carried out with circular economy practitioners to confirm, modify and validate the findings. These different strands of research have been synthesised in this paper to build a framework and process for designing for these circular behaviours. This research focuses on durable consumer goods as opposed to fast-moving consumer goods, with the latter designed to have much shorter lifespan and a lower unit cost [
26].
3. Methods and Concept of the Study
The aim of the research was to develop a framework for designing products and services to encourage desired circular behaviours. As discussed, understanding the importance of customer’s behaviour’s role in the development of circular business models has not previously been explored in a joined up way. Therefore, an explorative research approach was needed.
Figure 1 shows an overview of the iterative research process which was used to build the framework, the output of which is a description of desired circular behaviours as well as strategies for encouraging this behaviour. Both components were developed through a literature review, case study analysis and practitioner interviews.
Stage 1: Literature review
The first stage of the research was an extended literature review, focused on understanding how design for behaviour change strategies could be employed through both a product and aspects of a business model. DfBC literature was reviewed to understand the most applicable strategies for influencing behaviour and how these strategies could be built into a circular design process.
On top of the specific behaviour change research. The literature contributed to forming the model of desired circular behaviour by building a categorisation of B2C business models, as well as an understanding of how user behaviour influences a circular economy.
Stage 2: Case study analysis
The second stage was a case study analysis of different circular business model archetypes to form a basic model for circular behaviour, as well as insight into the approaches that companies use to encourage this customer behaviour. Case study analysis is a suitable research method for investigating contemporary phenomenon in a real life context and is suitable for exploratory work [
43]. Eight case studies were selected for study. As stated previously, business models are seen as a key enabler of a circular economy. PSS define the consumer experience and involvement; therefore, cases were chosen that: (i) adopted a B2C business model and (ii) were within the consumer goods sector. Cases were chosen which represented all of the three selected PSS business models categorised by Tukker [
12] as:
The case studies were taken from the Ellen MacArthur Foundation case study library, or found in circular economy literature, and were built on through information on company websites and additional literature. The list of case studies for each business model archetype is shown in
Table 1.
The results of the analysis were categorised according to business model archetype in
Table 1 and phase of users influence on product that this research is focusing on (e.g., during use or end of use). Each was analysed for the required user behaviour and how the business had sought to achieve this behaviour.
Stage 3: Expert Interviews
The Case study analysis provided high level detail of explicit user behaviours and strategies that companies had adopted to encourage them, for example; damaging products will result in charges. In stage 3 this initial model was iteratively improved through the use of expert interviews with circular economy practitioners. This stage provided a more in-depth understanding of both desired customer behaviours, as well as strategies for encouraging these actions. Practitioners were selected based on having experience with one, or a range, of the selected circular business model categories. Their role or experience and their organisation is shown in
Table 2.
Interviews were semi-structured and lasted between 30–45 min. These focused on four main topics: desired behaviours (if any) which helped circular business models to function, user behaviours which made circular business models more difficult, strategies used to encourage desired behaviours and a review of the preliminary model.
Interviews were then coded through a concept driven approach, where the key thematic ideas found through the literature review and case study analysis were used as the basis for coding [
52].
Stage 4: Synthesis and interpretation
The three iterative stages of: literature review, case study analysis and practitioner interviews were then synthesised to form two outputs. The first of these outputs is the model of circular behaviour (
Section 6), which describes the desired user behaviours for operating circular business models. The second output is the description of a process for designing for circular behaviours (
Section 7), which is developed based on design for behaviour change literature (
Section 4), as well as findings from the case study analysis and interviews on how businesses currently aim to encourage behaviour (
Section 5).
6. Synthesis and Interpretation
The findings from the literature review, case studies and interviews were triangulated, with the identified descriptive codes built up into 18 key themes, to form a description of the desired circular behaviours, as well as understand strategies for how business organisations could encourage certain behaviours through their business model.
6.1. Desired Circular Behaviours
The aim of the model of desired circular behaviour is to act as a guide for designers to understand what the key user behaviours that help circular business models to function are and therefore design products, services and other systems with these in mind. The model is not prescriptive and different behaviours will not be relevant for various product categories or business models, it simply highlights the categories of behaviours which may be relevant.
The model of circular behaviour is shown in
Figure 2, separated into the use and end of use phases. These behavioural groups were identified through the analysis of the case studies and interviews, through a thematic coding process. Each group is described in detail below.
6.1.1. User Ownership of Products
For products that are owned by users, a business or organisation generally has little control over what somebody does with a product when they have it. However there are still several ways in which organisations encourage desired circular behaviour.
During Use
Establishing a relationship involves registering a device with an original equipment manufacturer (OEM) or service provider, typically relevant when products are bought through a separate retailer. This allows businesses to engage with relevant after sales services, as well as informing users about any product issues. It may even allow businesses to plan end of life strategies.
Product care is an umbrella term, covering treating a product carefully, cleaning it or performing other preventative maintenance. Repair involves restoring a product back to a working condition and correcting any specific faults [
17]. For these components, the user carries out both of these actions.
Alternatively, a user could
Engage with product life extension services, using a service for general maintenance, repair or replacement parts. For example, Vitsoe provides services aimed at extending product life at nominal costs [
44], the key thing is that customers use this service.
A number of authors have discussed design for
Product attachment and ownership as a key circular design strategy [
10,
22,
28]. Also known as emotionally durable design [
65], the aim is for the user to form a strong relationship with the product meaning they take care of it, repair it if it breaks and postpone replacing it [
19]. Work by Baxter et al. [
41] suggests access over ownership business models clash with this model of product attachment, suggesting it may not be suitable for other circular business models beyond long-life ownership of products.
End of Use
When a user owns an object, one way of extending its lifetime is to
prolong replacement. This may be driven by product design strategies (design for repair, design for upgrade etc.) or a strong product attachment, but replacement behaviour can be driven by a vast range of factors such as consumer attitudes and situational influences [
66].
One way for businesses to capture value from used products is if the customer
returns the product, allowing the product, components or materials to be recirculated [
20]. Ensuring the item stays as a whole working product means that it maintains its highest level of value [
7,
21]. Alternatively, users could
sell, typically via a third-party site, such as eBay or through a second-hand store. Finally, users could
enable reuse by giving used products to friends, family members or through platforms such as Freecycle or donating to charity.
Material recycling is the lowest level of preserving value in a circular economy [
7], but in some product categories and circumstances it may be relevant. In these instances,
correct disposal/
recycling is necessary. This may involve separating materials for recycling, taking products to a designated recycling centre or in particular, not putting it in the general waste bin.
6.1.2. Provider Ownership
With products where the ownership is with the business or organisation, there is typically some form of agreement made, outlining what the relationship will be. This may define what is expected of the user and may also be supported by some kind of legal agreement. It is assumed that this defines that products must be returned to the service provider after a certain point. Therefore, the action of adhering to contractual obligations covers the act of returning products, along with behaviours such as keeping up with financial payments.
During Use
As with user ownership business models,
product care is still relevant along with
engaging with product life extension services. Less relevant, is that the user is required to make repairs to products themselves. However, it is not impossible that a user may be required to make repairs, for example MUD Jeans allows repairs on their leased jeans if the customer is based in more distant countries [
67].
Providing information concerns informing the business on the state of the product. This may happen at the start of use, to ensure that the previous owner left it in a suitable condition, for example with car sharing schemes. It could also be during use, to flag up any concerns or early signs of damage or need for maintenance.
Two types of behaviours that should be avoided are
product misuse and
damaging behaviours. Product misuse is where the product is used for tasks, which it may not be designed for, such as shaving a pet with a beard trimmer, or washing football boots in the dishwasher. This may lead to product damage as well as other issues such as hygiene. Damaging behaviours, are ones which are destructive in nature and go beyond normal wear and tear. The key difference between product misuse and damage (or abuse) is intent, which may require different design strategies [
58].
End of Use
In certain sharing services, to reduce the number of required products and maximise utilisation or sharing, it may be desirable that users of the service only have products for the exact time they are in use. This ensures that they are available for other users of the service. Behaviours contributing to this speeding up of sharing fall under
fast circulation of goods. For example, Toronto Tool Library limits the time that users can keep tools, meaning users only take them out when they are needed and therefore allow other users to access the tools, as well as reducing the amount of total tools needed to provide the service [
68].
One of the barriers to circular business models is the capital required to cover running costs, such as managing a reverse logistics network [
69], therefore it may also be desirable that user behaviour helps to
reduce these operating costs. These behaviours may manifest themselves in many ways. An example could be assisting with reverse logistics, by taking used products to a post office rather than being collected. Another example could be ensuring products are returned clean or in a suitable condition for the following user. A real example of this can be seen by the headphone business Gerrard Street, where customers are sent a flat pack of parts, which then need to be assembled and disassembled when sent back [
49]. This allows Gerrard Street to send their products in compact packages, which can fit through letterboxes, as well as reducing disassembly costs.
6.2. Business Strategies for Encouraging Behaviour
The case studies and interviews were further coded according to the Behaviour Change Wheel intervention functions [
64], shown previously in
Section 4.2.
All of the intervention functions were found through the case studies and interviews, apart from ‘Modelling’. This may be because businesses felt that this strategy was not relevant in the context of the circular economy, but the sample size is too small to be definitive and this aspect requires further exploration. One strategy that cannot be categorised clearly which appeared a number of times was ‘Trust’. ‘Trust’ between a customer and company can be crucial, for example, customers need to trust that by registering their details with a company they are not going to spammed with email marketing.
To inform actionable business strategies, these can be categorised according to the components of the business model; how a company creates, delivers and captures value [
70]. The business model canvas, outlined by Osterwalder & Pigneur [
70], is a tool to help visualise the key ‘building blocks’ of a business. In the case of circular business models, Lewandowski [
9] proposed the addition of a Take-Back system component to the canvas.
Table 4 provides a categorisation of the intervention functions found in the study and how they could be implemented as components of a business model. Other strategies that did not sit clearly in any business model component were rules regarding use (Restriction) and financial, or points based, Incentivisation or fines (Coercion).
8. Discussion
The model of circular behaviour proposed in this paper outlines the main behavioural targets to consider when designing product or business solutions for a circular economy. Some will not be relevant in every case and what is desirable will vary based on several factors, including, the product category, its cost, where it goes after use (directly to another user or back to the service provider) or the speed in which it is circulated. As described in
Section 2, circular design strategies to date have tended to focus on physical product design elements. This framework helps to encompass more of the human aspects into the field of circular design. The design for circular behaviour process offers designers a structured way to think about behaviour and can help enable them to consider how product strategies can shape this user role, as well as highlighting potential areas of leverage in the wider business model. There are, however, some matters which require further discussion and consideration.
The DfCB process was developed based on behaviour change literature and informed by interviews with circular economy practitioners. It incorporates two different design for behaviour change methods, Principles of Behaviour Change by Zachrisson & Boks [
79] and the Behaviour Change Wheel by Michie et al. [
63,
64]. Although both methods have been tested and applied individually in different contexts, the process brings these two together and introduces other novel elements, such as the business model strategies. It is therefore currently theoretical and should be viewed as a preliminary model until it has been tested in a practical application. It may also be the case that certain behaviour categories, particularly ones that do not involve specific actions, such as product attachment, are less suited to using the principles of the process outlined here. However, the model of desired circular behaviour can also act as a standalone tool for designers to use when considering new circular product and service ideas.
The employment of design for behaviour change strategies raises a number of questions. The first is whether aiming to change consumer behaviour is relevant in the circular economy at all. Different authors have taken different positions on this point. Piscicelli et al. [
25] advocate that DfBC strategies should be explored to increase acceptance of circular PSS. Moreno et al. [
28] argued against this, stating that by taking a more systems thinking approach, designers can produce offerings which are more accepted. Moreno et al. [
28] go further in stating that DfBC is not needed as a circular design strategy; if a holistic approach is taken for balancing user needs within a circular model, there is no need to for the user to behave in a more sustainable way. In fact, neither of these arguments are relevant to this piece of research. Firstly, the issue of consumer acceptance of new business models or motives for purchasing products is outside the scope of this work and therefore this paper explores a different application of DfBC as suggested by Piscicelli et al. [
25]. Secondly, as mentioned in
Section 1, DfCB is quite distinct from previous applications of DfSB, which has mainly focused on reducing energy use or environmental impacts at an individual level.
A related question to ask is whether DfBC strategies are the correct route to create this change in consumer behaviour. Arguing in favour of practice theory, Kuijer & Bakker [
82] highlight a number of key concerns with DfBC approaches, in particular design for sustainable behaviour. The most relevant of these concerns in this context are:
There is a risk of failing to achieve the intended behaviour change by focusing on specific use scenarios.
There is a risk of missing opportunities of larger scales of change by focusing too much on the scale of the individual level.
Deconstructing these points separately, the first argument that DfSB tends to focus on specific use scenarios, is important and should be avoided. This can be done by focusing on the user’s more general motives (beyond specific actions), as well as considering wider behavioural drivers as part of the COM-B model. The second argument is most relevant. To give a circular economy example, would focusing too much on ensuring users look after DVDs miss out the wider opportunity of shifting to a virtualised and more circular service such as Netflix? Potentially yes, but this goes back to the point that DfBC should not be viewed as the driver of systemic change, but a single strategy in helping bring about this change.
As discussed by Piscicelli & Ludden [
25] (and highlighted in
Section 1), the current discussion on transitioning to a circular economy has tended to underestimate the role of the user, mainly because the circular economy is viewed as a producer-led solution [
83]. This paper is not seeking to challenge that the shift to a circular economy should be producer-led, but highlights how customer behaviour does have an impact and that it should be considered and designed for where relevant.
An interesting and important point to mention is the changing aspect of ownership in the circular economy and how this could have profound effects on consumer rights and experience. Within the circular economy vision, companies have a heightened interest in the products they make and what happens to them after they have been used. Business models will be increasingly built around circulating products and therefore designing restorative systems around them, often as part of PSS. As more firms move towards these type of models, user behaviour will inevitably become increasingly of interest. This relationship may be exacerbated by the ability to track and monitor assets at all times through connected devices. As described by Webster: ‘
In some real sense ownership implies rights to determine what a person’s relationship is with products and property, to have right to use, abuse, abandon or dispose’ [
84] p. 139, in moving to an access over ownership economy, what sense of this personal control over products and behaviour could be lost? The ethics around DFBC have been discussed at length by other authors (for example Lilley & Wilson [
85] and Niederer et al. [
53]) and these discussions will be of continuous relevance due to businesses having further reason to move into the area of behaviour change.
Finally, although a range of research methods were used in this study, there are some limitations with the approach. Only eight case studies were explored, which is a relatively small number. The reason for this was down to two factors. The first is that it is acknowledged that there has been limited progression of circular business models in a B2C domain [
86], hence making it difficult to find strong case study examples. This is linked to the second factor, that case studies were only taken from the Ellen MacArthur Foundation case archives, or ones which were referenced in other literature, to ensure they were sufficiently circular in nature. Again, limiting the possible number. To help overcome this, circular economy practitioners were interviewed to provide a more in-depth understanding, as well as refining and validating the framework. Despite the combination of research methods, the model of circular behaviour is not exhaustive, but instead aims to highlight what is most prominent.