The circular economy (CE) has been gaining traction with consumers, industry stakeholders, researchers, and policymakers due to the promising opportunities to deliver benefits in line with the sustainability paradigm [1
]. The transition from a linear economy to the CE relies on individual organisations adopting circular economy business models (CEBM) [3
]. One sector that could benefit from greater adoption of CEBM is the electrical and electronic (E&E) sector [4
The E&E sector has increasingly been the subject of CE research in recent years due to its unsustainable production, consumption, and waste practices [5
]. As a trend, the product innovation process is speeding up, resulting in shortening of product lifecycles and early obsolescence [6
]. The rate of growth of demand for E&E products is constantly increasing [7
]. Often, E&E products are subjected to functional or technical obsolescence despite the potential for a reduction in overall lifecycle energy by extending their service life when compared to replacement with new models [8
]. Furthermore, the rise of smart objects means that E&E functionality is being added to a growing number of products [10
]. Unused E&E products are often hoarded instead of being passed on or disposed of [11
]. There is currently a limited second-hand market for E&E products [12
] and remanufacturing represents a market share of only 0.1% [13
]. As a result, waste electrical and electronic equipment (WEEE) is one of the fastest growing waste streams globally [7
]. The WEEE generation presents particularities due to the contained hazardous and toxic substances, as well as the valuable materials [10
]. Additionally, over 53 million metric tons (Mt) of WEEE was generated globally in 2019 and the waste generation rate in the sector is increasing by approximately 2 Mt year-on-year [7
]. Similarly, in Europe, WEEE is increasing 2% per annum [4
]. The E&E sector still operates in a predominantly linear economy with limited instances of reuse and recycling [15
], which results in the majority (60%) of the embodied resources being lost at end-of-life [7
]. The adoption of CEBM by E&E organisations could help to address these sectorial pressures by intrinsically linking their business value to the CE, thereby improving resource efficiency and encouraging improved management of WEEE for value retention and closed-loop value chains [16
]. However, research has shown that industry stakeholders are still unsure of the benefits of introducing circularity into their business practices [17
The ability of E&E organisations to measure the circularity of their products is critical to the development of actionable, economically viable and sustainable CEBM with measurable results [18
]. Currently, there is no standardised method of measuring circularity, which presents a key barrier to further CEBM implementation [19
]. Circularity indicators (CIs) that can measure and monitor the impacts of CE performance and the impacts of CE-led interventions are required to support the adoption of CEBM in practice [20
]. Research developing or reviewing CIs has been increasing over the last 5 years [21
]; numerous CIs have been proposed to capture circularity or an aspect of it [22
]. However, there is still much debate on the ability of existing CIs to capture the nuances and scope of the CE [24
]. Furthermore, there is evidence that the majority of organisations do not employ CIs or formal measurement methods to measure the circularity of their products; and a lack of CI data and CE knowledge are the greatest obstacles to the implementation and measurement of CEBMs [27
]. The development of sector-specific CEBM has been proposed as a method for reducing organizational knowledge gap regarding the CE and CEBM implementation [28
]. Saidani et al. [20
] highlighted the need for sector-specific CIs that account for the characteristics of sectorial activities to increase their use by organisations; hence, there is a requirement for further research to develop and test sector-specific CIs.
Thus far, there has been limited investigation of E&E sector-specific CIs [29
], and no study has been identified that addresses the range of CEBM possibilities for E&E products with a view to capturing the circular performance throughout the E&E products’ lifecycle. In response to the gap in the body of knowledge, this research seeks to answer the question: “How can E&E sector organisations measure and monitor the circularity of their products?” Answering this question, the aim of this paper is to develop and test a multidimensional set of CIs capable of measuring and monitoring the circularity of E&E products.
2. Circular Economy Business Models
CEBM build on the understanding of a business model (BM) as the way an organisation creates, captures, and delivers value [31
]. Similarly, a CEBM has been defined as a way that an organisation can perform its business functions to create, capture, and deliver value whilst improving resource efficiencies and closing material loops via CE practices [16
]. As such, a CEBM aims to deliver circular systems that are economically and commercially viable for an organisation [32
]. Successful CEBM relies on the supply and value chain also integrating circular practices, and customers adopting behaviours that enable circularity [33
Recently, researchers have increasingly adopted a dynamic view of CEBM by exploring how organisations transform their existing BM to CEBM by increasingly integrating CE principles [18
]. Several generic CEBM archetypes have emerged as tools for this transformation process [35
]. Pieroni et al. [34
] described these archetypes as dynamic conceptual tools that support identification of CEBM opportunities. Several archetypes exist within the emerging body of knowledge, and varying terminology is used to describe them. The five CEBM archetypes that capture those most commonly appearing in the literature are shown in Table 1
Sector-specific processes were deemed crucial to increase CEBM adoption and address practitioner uncertainties [28
]. Pollard et al. [18
] proposed a process framework for developing CEBM expressly adapted to the specificities of the E&E sector. The proposed framework identifies five key, interrelated layers, including (1) business strategy; (2) CEBM canvas; (3) CEBM challenges and enablers; (4) policy; and (5) CIs. The stages of the process framework represent decision-making steps for E&E manufacturers leading to the development of measurable CE implementation strategies (CEIS). The individual CEIS represent actions for the E&E manufacturers which, together for an implementation action, plan for the CEBM. The inclusion of CIs within the framework highlights circularity measurement as a core stage.
3. Circularity Indicators
The broad scope of the CE makes the development of CIs that capture the system difficult [36
]. However, CIs offer the opportunity to provide clarity to the complex system through the simplified presentation of information [20
]. In this way, measurable CIs can increase confidence in CEIS decision-making processes to address the lack of knowledge of the CE and CEBM amongst industry stakeholders [17
To date, there are no widely accepted or adopted standard CIs, and numerous, complimentary or competing CIs are proposed in both academic and grey literatures. Yet, most are incapable of addressing all five of the CEBM archetypes [26
]. Additionally, CIs established in academic literature have been criticised for not being verified through testing with their intended user group, resulting in a limited uptake [27
]. De Pascale et al. [22
] reviewed 61 CIs published between 2000 and 2019, from the perspective of the 3Rs (reduce, reuse, and recycle) and the three sustainability dimensions, finding that few CIs cover all three sustainability dimensions, and that recycling is the most considered of the 3Rs. In a review of 63 CE metrics published between 2007 and 2017, Parchomenko et al. [23
] took a wider approach by considering 24 elements of the CE and found a greater representation of metrics addressing circularity at a material level than at product and system levels, and a lack of metrics to capture value maintenance and longevity. Both studies made the distinction between CIs at the three systemic levels: macro- (national or regional), meso- (industrial parks or cities) and micro-level (organisations or products), as defined by Ghisellini et al. [1
]. Kristensen and Mosgaard [38
] stated that micro- and meso-level CIs are less prevalent than macrolevel CIs in the literature up to 2019. Contrarily, Saidani et al. [20
] argued there has been a marked increase in research of CIs at all three scales (micro, meso and macro) between 2010 and 2018, with most studies on macrolevel indicators originating from China and microlevel indicators originating from Europe. However, they agreed that microlevel CIs lack maturity, which limits their uptake in practice.
In response to the research question and the identified lack of E&E sector-specific CIs, this research is concerned with microlevel CIs that capture circularity at an E&E organisational product level. Currently, organisations most commonly use informal, unstructured methods to assimilate the impacts of their CEBM [27
]. Of the cross-sectorial, microlevel CIs proposed in the literature, Kristensen and Mosgaard [38
] identified the key themes and these are presented in Table 2
. Few micro-level CIs jointly consider all three pillars of sustainable development, and De Pascale et al. [22
] presented this as a gap for future research. Saidani et al. [20
] concluded, in a review of the 20 cross-sectorial, microlevel CIs, that recycling or remanufacturing activities were the most commonly considered, and only three address the specificities of a particular sector. In another review of cross-sectorial, microlevel CIs, Moraga et al. [26
] highlighted that none of the existing CIs addressed product functionality or sharing, therefore were unable to capture the circularity of alternative ownership or use business models. Equally, Elia et al. [25
] noted that very few of the existing cross-sector, microlevel CIs and evaluation methods consider product durability, which is key in the E&E sector due to the prevalence of planned obsolescence, echoing the point raised by Parchomenko et al. [23
Rossi et al. [39
] proposed requirements for the development of microlevel CIs, which they argued must facilitate the achievement of CE principles and be aligned to an organisation’s CEBM while addressing the triple bottom line (environmental, economic, and social performance). Predominantly, the existing literature draws alignment between the CIs and sustainable development [22
]. Although, there is currently limited alignment between existing CIs and the social dimension of sustainability, as most fail to capture the social impacts of circularity [40
]. The European Environmental Agency [41
] called for measurements of circularity to be aligned to product lifecycle phases (e.g., achievements made at material input, design, production, consumption, and end-of-life). Likewise, Pollard et al. [18
] also aligned CIs to the lifecycle phases of E&E products. The design, manufacturing, distribution and use, and end-of-life lifecycle phases are all critical for the circularity of E&E products [1
Kristensen and Mosgaard [38
], when publishing an analysis of 30 existing cross-sectorial, microlevel CIs, found there are three overarching types of CIs: (1) single, quantitative CIs; (2) analytical guidelines, tools and models; and (3) composite, multiple CI sets. Several authors noted the benefit of using multidimensional CIs which they argue are able better capture the complexities of the CE [25
]. Linder et al. [45
] suggested that a generic, microlevel CI is preferable to allow for comparisons between products across sectors. Conversely, Saidani et al. [20
] argued that existing, generic, microlevel CIs could form the basis for the development of sector-specific CIs tailored to a specific context, and that this specificity could further encourage adoption. This is echoed by Kravchenko et al. [36
], who contended that developing CIs tailored to sectorial specificities facilitates their implementation by ensuring the resulting measurements are contextually appropriate to support informed CEBM decision making.
By and large, two CIs have been developed to specifically address E&E sector activities: the WEEE Recycling Indicator Set [30
]; and Repairability Indicators for E&E products [29
]. However, both focus greatly on repairing and recycling associated with the end-of-life phase, disregarding the other opportunities and other E&E products’ lifecycle phases. Additionally, Rossi et al. [39
] proposed a set of 18 generic, microlevel CIs and applied them to a case study from the E&E sector, however they did not highlight how the specificities of the sector impacted the suitability of the CIs. In other instances, the Lifecycle Assessment (LCA) method has been employed to compare the suitability of multiple CEBM for E&E products [9
]. Studies in other sectors (e.g., building [46
] and agri-food [47
]) have identified similar knowledge gaps, and in response sought to identify sector-specific CIs. However, no study was found that proposed multidimensional CIs that addressed the specificities of E&E products.
Furthermore, there are numerous shortcomings in the ability of the existing, cross-sectorial CIs to address all of the CE practices and CEBM pertinent to the E&E sector, including the lack of coverage of product sharing and diverse ownership models [26
]; product durability [25
]; social sustainability issues [40
]; and implementation of CEIS across E&E product lifecycle phases [38
The following section presents the results of the qualitative workshop and the focus group. The presentation of the workshop results is divided into the two activities: first, the generation of the set of CIs for E&E products; and secondly, the rating of the relevance of the CIs to the E&E products and assigning them to three E&E product lifecycle phases as determined by the workshop participants: design and production, distribution and use, and end-of-life CIs. Finally, the results of the focus group are presented to validate the developed CIs.
5.1. Generation of Circularity Indicators
A total of 40 microlevel CIs were generated and refined in the workshop. Participants discussed the need for the generated CIs “to be flexible and pragmatic” to allow them to “be adopted at a generic level and product level for very different E&E products”. They also noted the challenge of differing “methods of data collection making direct comparison of performance difficult”. Furthermore, the CIs were proposed to address the key CEBM archetypes identified. The CIs alone do not ensure circularity and are designed to be used in combination with the other CIs in the list.
5.1.1. Environmental Circularity Indicators
Of the generated CIs, 25 are aligned with the environmental sustainability pillar (Env CIs), with great emphasis on product material content, reuse and WEEE management. The 25 Env CIs are shown in Table 5
Participants suggested that Env CI2 should relate to the “techno-economic viability of recycling, which depends not only on the recyclability of materials, but also on the product design and recycling infrastructure”; to address this, Env CI3 was proposed by the workshop participants. It was felt that there was some overlap between Env CI4 and the other Env CIs capturing the alternative material inputs. It was also noted in the case of Env CI5 that, while the use of certified sustainable materials supports circularity, use practices must be monitored to ensure the materials are not used in a linear manner. Participants showed varying opinions on the inclusion of Env CI6, with some resistance to its inclusion due to the necessity of certain hazardous materials for E&E product functionality. However, it was argued that it is relevant in the case that “real alternatives exist for a hazardous material, e.g., non-halogenated rather than brominated flame retardants”.
Ecodesign was seen as a key activity in CEBM implementation, therefore justifying the need for an Env CI to capture the effort made to comply with circular design guidelines and improve product design factors. Additionally, reuse was recognised as being one of the core principles of the CE, with preparation for reuse also recognised as being important in offering an opportunity to retain product value. The issue of energy recovery, captured by Env CI23, was contentious amongst the participants with a great variance in the considered relevance to circularity. It was argued by a few of the participants that energy recovery should be considered on a par with landfill, and therefore, not encouraged by the presence of an CI. While the majority of participants felt that though it was not the most preferable circular practice, it was still preferable to landfill in enabling resources to be recovered from waste.
5.1.2. Social Circularity Indicators
Nine of the generated CIs align with the social sustainability pillar (Soc CIs), as are shown in Table 6
There was some uncertainty about the definition of Soc CI1 and CI2; some participants perceived that there was overlap between the two CIs. It was observed that the measurement of an organisation’s involvement in circular networks was a complex issue and that “while an organisation’s involvement in circular networks demonstrates a level of commitment, it does not ensure good practice”. It was noted that an organisation must instead have circularity at the core of its business strategy. However, there was an agreement among workshop participants that “without stakeholders’ cooperation and commitment” a CE is unlikely.
5.1.3. Economic Circularity Indicators
Six CIs align to the economic sustainability pillar (Eco CIs), as are shown in Table 7
For the economic CIs relating to renting and leasing (e.g., Eco CI4), the participants reported that the CIs should refer to the market for “use instead of ownership, otherwise leasing or renting is only an alternative finance model” without strict alignment to the CE concept. It was proposed that the economic CIs referring to the market share or size (Eco CI4 and CI5) should be related to the company’s market for a product type and not the absolute market.
5.2. Relevance to E&E Product Lifecycle Phases
In the second workshop activity, participants were asked to assess the CIs relevance to E&E products and to determine the lifecycle phase to which they were applicable. Of the 40 CIs generated in the first activity, the stakeholder review process identified 20 CIs that were deemed to be highly relevant to E&E products, 15 CIs of medium relevance and 5 CIs of low relevance.
The participants identified and grouped three lifecycle phases: design and production, distribution and use, and end-of-life. Additionally, the participants assigned some indicators to “strategy” outside of the E&E product lifecycle phases; it was suggested that these CIs monitor and measure the impacts of decisions made at an organisation’s strategic level. Participants categorised four CIs as applying to strategy, as shown in Table 8
: two of high relevance (Env CI12 and CI25) and two of medium relevance (Soc CI1 and CI2).
5.2.1. Design and Production
Participants categorised 11 CIs as applying to the design and production phases of E&E products’ lifecycle, as shown in Table 9
. Design and production were grouped by the participants as they argued that the two phases are closely related and that impacts of decisions made at the design phase were realised through the outcomes during the production phase, therefore similar CIs were required for the phases to capture the results of those decisions.
Overall, the design and production CIs related to the materiality of E&E products were seen as highly to mediumly relevant to E&E products. The majority of the highly relevant CIs related to recycling or reuse. Energy use (renewable and total) also featured in the high and medium CIs, respectively. It was suggested that “the energy use during manufacturing should also be related to a functional unit (e.g., energy per kg of product)”. Participants noted that the CI could be relevant to the product’s use phase if normalised for the industry average for product type. Most mediumly relevant CIs referred to the materials content of the E&E product.
Env CI22, referring to the water consumption in the manufacturing processes, was deemed less relevant to E&E products; water use during the manufacturing phase was argued to have a relatively low impact. The technical lifetime of products (Env CI9) was also considered of low relevance to E&E products, due to the net-negative impacts that can occur from extending the lifetime of energy-using products. Additionally, participants felt that the average lifetime of the E&E products was a more relevant CI than their technical lifetime.
5.2.2. Distribution and Use
Participants identified 11 CIs from the list that applied to the distribution and use phase of the E&E product lifecycle, as shown in Table 10
. All the distribution and use CIs were rated either highly or mediumly relevant.
The CIs related to the repair and reuse of products (Env CI11, Soc CI6 & Eco CI5) were considered highly relevant by participants. It was recognised that there were two key issues that need to be measured: product repairability and access to repair services. The repairability of E&E products was considered dependent on product typology. Access to repair service, spare parts, and repair instructions (Soc CI6) was argued to be more relevant to business-to-customer business models as often business-to-business business models include maintenance and repairs in a PSS contract agreement. Additionally, three CIs related to PSS (Soc CI3, Eco CI3 & CI4) were regarded as highly relevant.
The CIs relating to sharing CEBM were considered of medium relevance by the participants, who recognised sharing platforms for E&E products as important “to improve access to products and encourage relevant circular end-of-life practices”. The intensity of product use (Soc CI4) was considered of medium relevance to E&E products to encourage the adoption of PSS or sharing business models. Although, it was noted that the relevance of this CI is dependent on the product type and usage patterns, with the nature of some E&E products “already requiring 24/7 operation”.
There was initial variance in participants’ responses to Env CI24, but they concluded that it is of medium relevance to E&E products to enable planned obsolescence to be addressed. Additionally, the comparison with Env CI9 would enable the impact of consumer behaviours to be assessed. In the case of energy-using products, it was suggested that Env CI24 must be considered alongside a lifecycle assessment to determine the optimal lifetime for the product.
A total of 14 CIs were categorised as related to the end-of-life lifecycle phase, as shown in Table 11
Of the eight CIs rated highly relevant, the majority related to recycling and associated activities. Reuse, remanufacture and refurbishment were also key themes in the highly relevant CIs. It was argued that Env CI10 was highly relevant to E&E products’ end-of-life activities, and that it was relevant for not only repair but also recycling activities where “manual disassembly leads to better yields but is often economically not viable due to duration of disassembly and the associated cost”. Additionally, Env CI14 was seen as highly relevant, especially in the case of E&E products where life-extension opportunities are limited but the distinction between the quality materials recovered, notably for critical raw materials, was also seen as highly relevant (Env CI18 and CI19).
Despite concern from participants in the first activity regarding its inclusion, Env CI23 was rated of medium relevance. Other CIs of medium relevance related to reuse and recycling. Two CIs were of low relevance (Env CI13 & Soc CI7), potentially due to the ambiguity of these CIs which addressed similar issues as some of the more highly rated CIs.
5.3. Focus Group: Manufacturer of Printers
Following the workshop, the developed set of CIs were then piloted in the focus group to validate their applicability for E&E sector organisations and their effectiveness for measuring and monitoring CEBM. To pilot and validate the CIs, it was first necessary to identify the PRINT-MAN’s CEBM in the form of the CEIS to be measured. Therefore, the focus group comprised two activities: first, the development of PRINT-MAN’s CEBM Canvas and related CEIS; and second, the association of the latter with the CIs.
5.3.1. Printers Manufacturer’s CEBM Canvas
During the first activity of the focus group, the participants applied a systematic process to develop a CEBM for the PRINT-MAN. The PRINT-MAN’s CEBM was expressed in terms of CEIS to be realised. Discussions between the focus group participants led to the development of 68 possible CEIS across the nine components of the CEBM Canvas. The CEIS proposed were seen as advantageous and feasible for the PRINT-MAN’s business, according to their product, service offerings and customer profile. The CEIS represent the implementation plan of PRINT-MAN’s CEBM which are to be measured via the CIs.
The participants then categorised their potential CEIS according to their implementation timeframes: short-, medium-, and long-term. This was determined according to the PRINT-MAN’s actual business constraints and their readiness to conduct the CEIS. The short-term CEIS were defined as actions that could be fully realised within the next two years, whereas medium-to-long-term CEIS were defined as requiring a longer implementation timeline. The participants identified a total of 19 short-term CEIS (1–19) to be implemented from their developed CEBM, seen in Table 12
. The short-term CEIS were then categorised by their related E&E product lifecycle phase; of the 19 short-term CEIS, 7 actions were to be implemented in the design and production phase, 15 actions were to be implemented the distribution and use phase, and 6 actions were to be implemented in the end-of-life phase. Some of the actions overlapped in two phases and so were listed twice.
5.3.2. Measuring the Printers’ Manufacturer’s CEIS
In the second activity, the focus group participants were asked to associate CEIS 1–19 to the relevant CIs from the generated list. Of the 35 highly or mediumly relevant CIs from the workshop, the participants selected a shortlist of nine CIs to measure the outcomes of their CEIS: Env CI2, CI12, CI15, CI16, CI19 and CI25, Soc CI9, and Eco CI3, and CI5. The nine selected CIs covered all four of the lifecycle phases identified by the workshop participants and all three of the sustainability pillars. The results of the final activity associating the CEIS 1–19 to the nine CIs can be seen in Table 13
. The results demonstrated that the CEIS could be captured by the nine selected CIs.
The research set out to answer how E&E sector organisations can measure and monitor the circularity of their products. In response, the research aimed to generate, rate, and validate microlevel CIs relevant to E&E sector products. The adoption of CIs is understood to be key to providing organisations with the data required for CEIS decision making during the transition from linear to CEBMs. However, thus far there is still great discussion over what constitutes the most suitable method for measuring circularity and whether existing microlevel CIs can effectively measure the circularity of E&E products.
This research is the first to provide E&E organisations with CIs that are associated with the key lifecycle phases of their products, therefore contributing to the advancement of knowledge in circularity measurement and monitoring within the E&E sector. Implications can be drawn from the findings for E&E sector organisations wishing to measure the circularity of their products and apply associated CIs. The resulting CIs are intended to provide E&E organisations with a way of assessing the impacts of products on their transition to the CE through the implementation of CEBMs. E&E manufacturers using the developed CIs to measure the circular performance of their products should first establish their ability to reliably collect the required data, which may lead to a customisation of the CIs to be considered. Where data are not available for key CIs related to their CEBMs, such as those rated as highly relevant, E&E manufacturers should be encouraged to develop procedures internally and with their supply chain partners to collect the required data.
Due to the exploratory nature of this research, standardised calculation metrics have not been offered for the developed CIs, which could be seen as a potential limitation. Future research should look at establishing standard calculation metrics for the CIs, especially those with high relevance to the E&E sector, with the aim of ensuring the comparability of the data between organisations.
It was not possible to represent all of the wide-ranging E&E product types in the data collection process. Building on this research, future research could aim to validate the CIs by collecting data for the 20 high and 15 medium CIs during the realisation of the CEIS for additional case studies of different E&E products (such as computers, televisions, refrigerators, washing machines, etc.). By doing so, the studies could aim to establish the availability and usefulness of the derived data to the E&E organisations in evaluating the circularity performance of their products, acknowledging the importance of application to real-world case studies to further strengthen the research findings.