Circular Business Model Frameworks: A Review

The circular business model (CBM) concepts are vast, interconnected, and emerging. Research to date has been somewhat fragmented, and there would be value in focusing on the systemic identification of the connectivity of the topics around CBM. Furthermore, the business model innovation (BMI) process and business model implementation were identified as two separate spectra of research that should be seen collectively and added to the literature. This article reviewed 256 articles (solely focusing on “CBM frameworks”) published between 2007 and mid-2022, collected from the Scopus database, and analyzed using the content analysis method to identify the research gap/s. Results showed that under circular business model innovation (CBMI), the innovation process and their associated process modeling, archetypes, tools, experimentation, digitalization, and innovation via the inclusion of circular economy (CE) principles and sustainability in BMI were highlighted. From the CBM adoption/implementation perspectives, business ecosystem, technological innovation, product lifecycle management, CBM value dimensions (e.g., value proposition, value creation, and delivery), organizational capabilities, and dynamics were investigated. Topics around sustainability and circularity principles, strategies and organizational performance, CBM value streams, digitalization, and product-service systems were topical issues of the circular supply chain (CSC). A conceptual framework for gaining circular competencies integrating all elemental issues throughout the CBM development process (e.g., innovation, adoption within CSC) has been progressed. Based on the review, this article defined a circular business model as a business model that fundamentally applies one or more of the principles of CE at various product/service/material lifecycle stages, for which sustainability-focused technological innovation, collaboration among business ecosystem partners, and enhanced dynamic capabilities of any organization are pre-requisites . Several research gaps were identified with potential avenues for future research directions, which will be helpful for policymakers, business organizations, and researchers.


Introduction
Circular economy (CE) is now considered a saving grace to eliminate the current linear wasteful economy.The circular business model (CBM) is one of the most critical and challenging elements for transitioning to CE. Various frameworks are being developed to define and apply these concepts.The distinct difference between CE and CBM frameworks can be conveniently visible by analyzing core elements developed by organizations and researchers.According to Circle Economy's CE framework, there are three core and five enabling elements, as shown in Figure 1.The core elements of the CE framework represent broad and overarching concepts associated with resource flow (i.e., a theory developed by [1]), based on waste hierarchy and behavioral concepts around sustainability (e.g., 10R and 5R frameworks developed and utilized by several authors mentioned in [2]) and principles-oriented postulation by Ellen MacArthur Foundation [3].On the other hand, rethinking the business model within the CE is considered one of the enabling elements of the framework that corresponds to identifying increased value-based opportunities around products and services.https://www.hos.pub Figure 1.Elements (core and enabling) of CE framework, adapted from [4]. 1 Strategies for resource cycling developed by [1], 2 10R framework developed by [5], 3 5R framework illustrated by several authors, as mentioned by [2] and 4 Ellen MacArthur Foundation [3].
Business model canvas (BMC) developed by Osterwalder & Pigneur [6] consisted of multiple steps such as 1) business model canvas, 2) pattern and archetypes, 3) design, 4) strategy, 5) process, and 6) outlook.Businesses create value by incorporating other enabling elements such as design thinking, digital technology application, collaboration, and knowledge sharing among different teams, stakeholders, and organizations.CBM frameworks are (business) objective-specific.It shows an operational mechanism and critical pathway to achieving CE, while CE frameworks incorporate core concepts around sustainability and principles of CE.Thus, this review article argued that CE framework and CBM frameworks are distinct in terms of scopes (e.g., product system or service system or combined), elements (e.g., value and strategy-based approach), and orientation (e.g., business ecosystem and context).This article aims to analyze framework-specific studies on CBM.
The main contribution of this review article is to provide a holistic picture of CBM frameworks which were seen in a segmented manner (i.e., specific sectors such as textile or automobile, the particular issue, for example, product design, business model innovation tool, process framework, and others) previously in the literature (see Section 2-Literature Review).This study analyzed 256 articles on circular business model innovation (CBMI), implementation, and circular supply chain perspectives.After reviewing the articles, this study develops a conceptual framework and identifies several potential future research directions.
After this brief introduction, the article is organized into several sections.Section 2 provides a short literature review of previously published articles on CBM, focusing on frameworks only.Section 3 describes the research methodology; Section 4 provides an in-depth literature analysis.Section 5 discusses issues based on the study's findings, and Section 6 highlights some of the research gaps and future research directions.Section 7 ends with the conclusion.

Literature Review
Previously published review articles indicated that when it comes to reviewing only frameworks that solely focus on CBM, they have yet to be published in the academic literature.To identify the relevant review articles on CBM, "circular*" AND "business model*" keywords were used in the Scopus database.The method underpinning the literature review is explained in Section 3.1.
Several authors partially reviewed the CBM frameworks, focusing on different issues.Most of the studies developed conceptual frameworks after reviewing relevant literature on CBM.In the area of CBMI, de Kwant et al. [7], Geissdoerfer et al. [8], and Bigliardi & Filippelli [9] partially reviewed the CBM frameworks.Santa-Maria et al. [10] framed the CBMI research field, process, and practice, while Nußholz [11] clarified CBM concepts with resource efficiency strategies.Pietrulla & Frankenberger [12] tackled the antecedents, moderators, and outcomes of CBM, and Kanzari et al. [13] investigated the financial performance, including design thinking of CBMI.Bocken et al. [14] focused on frameworks associated with tools and conceptual frameworks, and business model dimensions and characteristics were analyzed from the companies' value creation effort by Ludeke-Freund et al. [15].On the other hand, Ludeke-Freund etal.[15] analyzed value creation by companies using the concepts of closed-loop material systems and industrial symbiosis (IS).Lewandowski [16] investigated the implications of CBM at the micro level using Osterwalder & Pigneur's BMC [6].
Many authors integrated elements of the BMC and ReSOLVE framework.Rosa et al. [17] focused on the classification framework and CBM archetypes.At the same time, Wasserbaur et al. [18] and Lopes de Sousa Jabbour [19] analyzed the framework related to tools, frameworks, organizational changes, market environment, and governmental policies, respectively.Pangarso et al. [20] analyzed the implications of the ReSOLVE framework on micro, small, and medium enterprises.
Partially, some of the studies reviewed some conceptual and theoretical frameworks either considering a specific sector such as renewable energy [21], luxury fashion and textile industry [22,23], construction industry [24], car sharing-related CBM [25], the role of CBM in the manufacturing and service sector [26], CBM adoption in the electronic product sector [27], archetypical CBMs in construction [24] or automotive parts remanufacturing [28].
Some authors tried to tackle other issues related to CBM, such as Pieroniet al. [29], who attempted to integrate sustainability with CBMI.A similar approach was taken by Khan et al. [30], who investigated CBM-related frameworks integrating sustainable development and Industry 4.0.Milios [31] researched policy mixes and interconnection between CE and CBM.Circular supply chain (CSC) and supply chain circularity-related issues were tackled by some researchers, such as Kühl et al. [32], focusing on product-service systems (PSS), the implication of the Re-SOLVE framework in CSC by Lahane et al. [33] and leveraging capabilities of technology developing CBM by Abideen et al. [34].
However, none of the studies comprehensively reviewed various types of frameworks (regardless of the types, such as conceptual, theoretical, and hybrid types) because the studies proposed by the authors to understand the extent of the CBM research to be applied as 1) CBM innovation process, 2) CBM implementation/adoption and 3) circular supply chain associated with CBM, integrating all the segmented components in the broad area of CBM research (i.e., especially from the perspective of frameworks).
Although some of the authors' papers (reviewed in this article) expressed their explicit opinion on developing CBM for a specific sector, aspects (e.g., product design, finance, business levelmicro, meso, macro), on many occasions, references were taken from CE transition frameworks, not explicitly associated with CBM-frameworks.This article's material collection and selection process exclusively focuses on CBM frameworks by applying extensive and established search criteria, ensuring that frameworks corresponding to CBM are only covered for further analysis.Details are provided in Section 3.1.

Research Method
A literature review is essential to scholarship since it aids in thoroughly exploring and organizing a particular field of study [35].Moreover, a helpful literature review can increase knowledge in the subject area by highlighting crucial conceptual ideas that can lead to new theories and new areas of research [36].This research article implemented the 4-steps content analysis research method (namely, material collection, descriptive analysis, category selection, and finally, material evaluation) described by Mayring [37], which was previously used by CBM researchers such as Bocken et al. [14], Antwi-Afari et al. [38], Henry et al. [39] and others.The following section merged material collection and evaluation steps for simplicity.The steps and process of content analysis can be found in detail in the study by Mayring [40].

Material Collection and Evaluation
For this review, academic journal articles, book chapters, and conference papers have been identified using keywords such as "circular*" AND "business model*" in the Scopus database as "topic".Geissdoerfer et al. [8] previously applied this keyword string.The search was undertaken in mid-June 2022.With the keywords, the total number of documents retrieved was 1301.As previously mentioned, frameworks are one of the vital research outputs produced by the researchers connecting segmented critical topical issues.This article tried to understand and identify interconnected themes and topics that have yet to be investigated.For this reason, the keyword "framework" has been given in the refined search box in the database, and 964 articles were found.
Each abstract was then studied to understand the relevance of the articles in the final collection for this review.The inclusion criterion was that an article must present a theoretical/conceptual/analytical framework or any hybrid-type framework predominately focused on CBM.
The definition of the various frameworks can be found with the reference to Pacheco-Vega [41].When a framework comprises the different theories and theoretical constructs that help explain a phenomenon, it is called a theoretical framework.The conceptual framework illustrates the concepts one must know to understand a particular phenomenon without pretending to create causal links across variables and outcomes.At the same time, an analytical model that helps to explain how a specific type of analysis (associated with data) will be conducted is called an analytical model [41].In addition, when researchers mentioned developing a specific framework (e.g., theoretical, conceptual, analytical), a particular category is assigned to the research paper.When it is not mentioned (i.e., mainly for the case of the hybrid framework), a specific hybrid category (described in Section 3.2.4) is assigned to a paper.In some places, it is seen that within these retrieved articles, some developed frameworks have yet to relate to CBM, which were then excluded.Similarly, although some articles might focus on CBM, the need to create a framework was excluded.In these cases, the full text of the articles was reviewed.
In some cases, despite mentioning CBMs in the abstract, it was necessary to go through the full text of the articles to understand whether any framework has been shown (in the form of a figure or table) in the article.After reviewing the articles with these inclusion and exclusion criteria and, in some cases, the full-text search, 266 articles have been identified for preliminary review.A total of five of the articles were finally excluded as those were in languages other than English (i.e., the English language was not selected in the first place during the search as it was seen from the previous experience of the authors that in some articles abstract appeared in other languages, but full-text articles were found in English).However, in this case, it was found that five of the articles, either in different languages or full text, were not available at the time of the search to consolidate the collection of the articles for this review.Finally, 256 articles were found relevant and qualified for detailed analysis.In the final collection of the articles, sustainable business model (SBM)-related research is also included as it is found that many of the researchers combined these two business models (CBM and SBM) aspects in developing their frameworks.Geissdoerfer et al. [8] mentioned that a CBM is a subset of SBMs.Besides, journal articles (222 papers, 87% of the collected materials), 25 conference papers (10%), and nine book chapters (3%) are included.It is believed that in Scopus, peer-reviewed conference papers and book chapters were indexed.
This evaluation process (the last step of the content analysis process was merged with material collection) makes subsequent processes reliable.Validation tests conducted by two researchers concurrently utilizing the deductive and inductive methodologies provide rigorous validity.Both intra-rater and inter-rater reliability were used to gauge how reliable the content was (i.e., with the inclusion and exclusion criteria).Following material collection, the researchers entered all pertinent data from the chosen publications into a spreadsheet program, reducing repetitive mistakes.

Journal Outlets
To understand the extensive range of characteristics and interconnected contents of the CBM-related frameworks (i.e., CBM, CBMI, and its adoption strategies and implementation techniques), papers were identified from more than seventy journals.Among the journals, Journal of Cleaner Production (49 papers), Sustainability (41 papers), and Business Strategy and the Environment (21 papers) were identified as the top three journal outlets publishing papers on this issue.

Yearly Publication Trend
The timeline and the yearly publication indicated that the first article on the CBM topic started in 2007 and steadily increased from 2014 to 2016.Between 2007 and 2014, papers were not found in the collected material for this review.The number of publications increased linearly until 2021.

Country of Publication
In total, 45 countries contributed to the research published in the CBM research area, among which Italy and northern European countries (e.g., Netherlands, Denmark, Sweden, and Finland) are at the forefront.These countries published papers on new tools, the CBMI process, experimentation, and identifying critical success factors for the CBM transition from linear business models.Researchers from the UK also contributed to theoretical scholarship and knowledge development.Countries such as Australia, the USA, and China published a few papers.As emerging economies, Brazil and India also focus on the research spectrum.Figure 2 shows the geographical distribution and the number of publications.The bubble size indicates the number of publications in the regions (on the upper side of the figure).

Type of Frameworks
Figure 3 shows the distribution of various types of frameworks.First, the nature of the frameworks needs to be shown, as this was the unit of analysis of the material collection.Primarily, three basic types of frameworks emerged in the articles.Among them, the conceptual framework represented the highest number (131 articles) followed by a theoretical framework (28 papers), and an analytical framework (25 papers).Some articles developed a hybrid framework combining theoretical or conceptual and analytical frameworks.As the name suggests, these articles develop the conceptual/theoretical framework and then apply various analysis methods to quantify or validate their framework with numeric/quantitative analysis.In that case, the authors used data collected by multiple techniques such as surveys and interviews and, in some cases, material and impact assessment-specific data to use in the hybrid framework.
The category "generic" refers to the papers that used previously applied frameworks for their analysis.For instance, some studies have applied BMC as a framework for proposing business opportunities.They had yet to develop any novel framework, but they utilized the previously developed ones and integrated various factors and elements to identify adoption and innovation opportunities.

Category Selection
The category by which this review article was developed is segmented into three main research problems.Firstly, studies focused on developing frameworks and exclusively discussed research topics related to BMI.On the other hand, the second category of the articles primarily reviewed the adoption and implementation aspects of CBM within business organizations or at the ecosystem level.Both categories published the same percentage (47%) of articles in the collected papers (Figure 4).However, the main delimiting factor between these two categories is the strategic discussion arising from the documents which were more in the second category of the articles (i.e., in some places, the authors directly mentioned that their framework is for implementation at an organization, and single and demonstration of multiple case studies).In a nutshell, the first category represented "what to innovate" (e.g., tools, experimentation, innovation process), and the second one showed "how and where" to adopt it in an organization (e.g., by collaboration in ecosystem and technology deployment in value creation and proposition).Despite the critical importance of characterizing the value chain from a product/material lifecycle perspective to identify opportunities and gaps, very few articles focused on circular supply chains (i.e., compared to the other two categories) within the context of CBM (i.e., only 6% of the articles published in this area).Three of these main categories were then divided into subcategories, as shown in Figure 5, indicating that innovation process-related studies emerged as a distinct segment under the broad BMI-related studies.The categories and subcategories were identified based on the specific problems the authors wanted to address/attempt to solve mentioned in the articles.CBM value dimensions were also recognized as the second most crucial category discussed widely in the literature.Details of the dimensions are given in Section 4.1.5.Authors developed various CBM classifications and archetypes for innovation frameworks, while some papers applied those typologies to a specific use case or sector-specific CBM implementation.That is why these two subcategories were repeated twice.Organizational capabilities and dynamics are the categories that elaborately highlight the entrepreneurial characteristics of an organization that is transforming and adopting CBM.Challenges and barriers, tactical strategy, capital allocation, and the organization's willingness to change BM were also uncovered.Institutional and stakeholder engagement, environmental stewardship, proactive attitude integrating societal value into value creation, and value proposition dimensions were some of the topical issues identified in these subcategories.In this type of analysis, around 48 papers were published.

Analyzing Papers on BMI Frameworks
Circular business model innovation-related papers discuss innovation process, tool development, CBM archetypes, business model experimentation, CBM value dimensions (i.e., value proposition, value creation, and delivery and value capture), digitalization, sustainability, and circularity principles inclusive of CBMI and matrices, and assessment was critically analyzed.This subsection includes CBM archetypes and classification, circular business model innovation process (CBMIP), tool development, business model experimentation, CBM value dimension analysis, sustainability, and circularity in BMI, digitalization, and technologies, and metrics and assessment were reviewed in detail.

CBM Archetypes and Classification
The academic literature surrounding CBMs highlights the diversity influenced by variations in industry, organizational structure (e.g., small and medium enterprises-SMEs, large corporations, start-ups, and others), and technology integration.Due to this variability, different CBM archetypes have emerged.These archetypes are typically defined by R-strategies (e.g., reduce, reuse, recycle) and ReSOLVE actions (e.g., share, loop, virtualize), customized for specific industries or products/services.Furthermore, new CBM classifications are introduced by separating the life cycles of technical and biological products.Businesses must comprehend these categories to choose suitable models and distribute resources efficiently.Nonetheless, a cohesive framework for CBM archetypes needs to be included in the literature.
Studies by Rosa et al. [42], Ludeke-Freund et al. [15], and others highlight the need for more research to fully understand the shift to CBMs and their application in a CE.These studies demonstrate the complex scope of CBMs.The significance of design in advancing circular strategies [39,43], the role of circular strategies in distinguishing circular from linear models [11], and the investigation of business models in the industrial symbiosis and agri-food sectors [44,45] are some of the key findings.
Essential themes include the importance of the principles of repair, reuse, and redistribution [46], the role of digital platforms [47], the difficulties and motivations of circular economy business models [48,49], and the requirement of switching from linear to circular models [50,51].Pieroni et al. [52] identified twenty CBM archetypes, while Guerra et al. [53] highlighted the disruptive potential of sharing and product-as-a-service models.
Based on the review, describing archetypes is particularly challenging as it involves various considerations in terms of industries and influencing factors.However, based on the factors that work as a building block of the CBM, archetypes can be broadly categorized as shown in Figure 6, which could be helpful for any firms devising specific types of CBM according to the requirements.At the same time, such a detailed understanding would help innovate new CBM types as there is an ongoing trend of developing a hybrid business model.By nature, it is conveniently understood that as CBM is composed of many variables to be considered, future business models would effectively use more than one strategy or innovation pathway.

Innovation Process
Various authors developed a CBM innovation process framework, and this research category was identified as one of the highest-numbered studies in the literature.The following section describes multiple innovation processes described by the authors.

Process Framework Typology
Some authors considered industry best practices and case studies to develop innovative process frameworks.Innovation process frameworks and typologies were developed in two segments: 1) stepwise process and 2) adding essential components such as product lifecycle perspectives, strategic partnerships, and identified circularity indicators.Sustainability and circularity-oriented business model strategy and the organization's dynamic capabilities were considered core elements of processing steps development.A summary of the articles is shown in Figure 7.

Green Products and Eco-innovation
Green BMI and eco-innovation were identified as CBM innovation processes.Lindgren et al. [54] identified two sets of characteristics for Green Business Models, which concentrate on environmental consequences and business efficiency, covering green elements (such as excess energy and waste management) and economic factors (such as turnover and expenses).Popa & Popa [55] identified that CE works as a source of knowledge management in the workplace for business process modeling and analysis.
In the case of eco-innovation, Sehnem et al. [56] highlighted the importance of dynamic, relational, and absorptive capacities in implementing eco-innovation for CBMI, with an emphasis on activities such as waste management, eco-design, product leasing, and collaborative commerce.Vence & Pereira [57] highlighted that eco-innovation and CBM play crucial roles in creating a CE, necessitating systemic and intricate thinking utilizing both top-down and bottomup strategies.Scarpellini et al. [58] incorporated eco-design, eco-innovation investments, environmental R&D, and circular energy into the dynamic capabilities framework, emphasizing the significance of certification standards and ecological accounting for innovation and circularity.

Challenges and Barriers, Solutions and External Contextual Factors
• Challenges and Barriers In the CBMI process, challenges and barriers businesses face depend on the organizations' sizes and structure.At the corporate level, the process is relatively slow [59].Linder & Williander [60] identified fundamental differences between CBMI innovation and legacy business model https://www.hos.pub(LBM) innovation.Roos [65] found that companies focus on profitable value chains with social dilemma situations and monetizing "waste" value streams.Lack of understanding of social needs was identified as a barrier to organizational transition management and in circular start-up by Hofmann & Jaeger-Erben [66] and Henry et al. [67], respectively.Balancing these factors is often challenging.Strategic decision-making in forerunner companies, Lehtimäki et al. [68] and Guldmann & Huulgaard [59] found that there is a problem of path-dependency and lock-inphenomenon and often it is difficult for companies to balance between internal and external elements, counted as organizational inertia.Pedersen et al. [69] found the inertia and lack of competitive dynamics and supply chain coordination as barriers in the case of circular design strategy in CBMI.Such reluctance/hesitancy occurred due to uncertainties in cost and revenue, identified by Linder & Williander [60] in the case of PSS.In addition, Guldmann & Huulgaard [59] also found that there are employee barriers, market barriers, and institutional barriers.

• Strategies and Innovations as Solutions
Several researchers provided solutions to overcome challenges.Authors highlighted value creation by diverse means.For example, creating value from waste [70], remanufacturing (upgrading) and disruptive product-service system (PSS) [71], and service-oriented technology sector (ICT system) implementation [72].Santa-Maria et al. [10] suggested an organizational change process focusing on sustainability and circularity-focused CBMI.Piispanen, Henttonen & Aromaa [70] emphasized increasing organizational capabilities, training and dedicated aspiration investment, business ecosystem alignment, and reverse logistics.In addition to ecosystem alignment involving new partners, Nyström et al. [73] mentioned customer channel development.Agrawal et al. [74] focused on circularity and material traceability and found that crossorganization sharing, system interoperability with technologies, and strategies for traceability should be part of the solutions.Backcasting and eco-design-focused decision-making in the service-oriented technology sector for new resource value propositions was suggested by Heyes et al. [72].Adopting new thinking and business practices [68], user behavior and optimizing asset use through data monitoring and analysis [72], early-stage opportunity exploration in the CBMI process [75], the role of business consultants to influence company top management [66], incentives to promote circular consumption and production [76], stakeholder influence [77] were identified some of the critical strategies identified by the authors.Santa-Maria et al. [10] specifically mentioned that the impact of sustainability strategy on the CBMI process, the significance of top management's involvement in the CBMI process, and the moderating effects of organizational culture and ambidexterity on CBMI are critical.
Synergies creation and internalization of externalities through system sharing and data exchange were suggested by Koutras et al. [78].Jabbour et al. [77] suggested implementing CE principles using certification (e.g., ISO 9001 and 14001 certifications) to manage intricate relationships, stakeholder pressure, and organizational sustainability.Chirumalla et al. [75] suggested a multi-stakeholder CBMI process to create a win-win scenario in the value-creation process.Circular product design and collaborative partnership in case of goal congruence, resource sharing, and finance alignment were highlighted by Brown et al. [79].For circularity promotion, Unterfrauner et al. [76] mentioned community awareness.
• External Contextual Factors There are several external contextual factors identified by the authors, such as environmental issues [80][81][82], technology and infrastructure [80][81][82], and regulatory/political aspects [80][81][82].In addition, Han et al. [80] found the critical importance of knowledge and information, sociocultural aspects, supply and partner network, and the market as key external contextual factors.Urbinati et al. [83] specified that customer management, economic/financial, and (external) organizational aspects influence CBM creation.Changing utilization partners was highlighted by Mishra et al. [82] in the case of CBM transition in the textile value chain.Pedersen et al. [69] believe that the perceived value of stakeholders (e.g., interests and business models) in the CBMI process is crucial.At the same time, Koutras et al. [78] emphasized behavioral change toward service use and external market pressure integrating reduction, reuse, and recycling as critical contextual factors.

Business Model Design
Some authors developed frameworks that were directly related to business model design and understood as a part of the business innovation process.Centobelli et al. [84] focused on business model design.They developed a theoretical framework that considered multiple cycles of principles of 3R (reduce, reuse, and recycle), sustainable value networks, and organizational perspectives to identify key performance indicators and assess different degrees of circularity in business models.Bigliardi et al. [85] developed an integrative theoretical framework to design an effective business model for CE by including behavioral theories and constructs.The framework is applicable for farm managers to understand the drivers behind the consumer's purchasing process and behavior.According to the authors, the theory of planned behavior, norm activation theory, and value-belief-norm theory are the most used theories in the environmental and psychological domain.More details on the theories can be found in [85][86][87][88][89][90].Tunn et al. [91] focused on business model design.The authors developed a business model framework based on resource strategy, revenue model, consumer effort, and objective to (decrease/increase) consumption level.The results of this study indicate that the business strategies that reduce overall consumption levels and customer effort are the most promising for promoting sustainable consumption.Furthermore, the authors discovered that various business models on the market could help various client categories engage in sustainable consumption.

Tool Development
Tool development for CBM innovation is a popular theme in the research spectrum.Here, tools refer to systematic techniques, both dynamic and static, that help capture the critical elements required to identify innovation opportunities and progress into successful BMI.
Traditional linear BMI applied widely available tools such as the business model canvas (BMC) developed by Osterwalder & Pigneur [6] or the lean canvas developed by Maurya [92], which brought all the required building blocks of a business model into one single paper.Various teams of an organization then brainstormed these.Some authors directly applied the BMC as the framework for illustrating specific circular business cases.For instance, Gunasekara et al. [28] used the BMC to remanufacture automotive parts.Salvador et al. [93] applied the BMC components to identify opportunities in the bioeconomy sector.For sustainable business model development and initial innovation-related exercises, Bocken mentioned Reis' Lean start-up principle development [94].As CBM innovation is a relatively new and progressive research area, tools and frameworks are emerging rapidly.Some studies that developed new tools and frameworks for CBM innovation are summarized below.On many occasions, sustainable BMI worked as an inspiration for tool development.
Islam & Iyer-Raniga [95] developed a canvas-like CBMI tool called circular business model value dimension canvas.Figure 8 shows various tools for CBMI.It is also acknowledged that there are other tools available in the literature.However, these articles were retrieved as the primary search criteria were associated with frameworks for CBMI.

Business Model Experimentation
Nancy Bocken and her colleagues mainly conducted studies related to business model experiments (BME).This specific type of study is primarily based on action research and requires substantial interaction and an iterative process.Figure 9 summarizes the studies.

CBM Value Dimension Perspectives
CBM dimensions or value streams (value proposition (VP), value capture (VC), value creation and delivery (VCD)) are the core of the CBM innovation.In VP, the main question is, "What value is provided and to whom?" [96].A VP is one of the critical aspects of CBM innovation.Some authors investigated PSS-focused VPs.On the other hand, VC is a segment of the interconnected building blocks of BMC of key activities, key resources, and critical partners.However, it is often hard to separate value delivery (VD) aspects from the VC, as CBM, by its very nature, connects the idea of co-creation, collaboration, and cooperation with customers and business ecosystem stakeholders.VD mainly focuses on delivering value through various channels (forward and reverse).
Within organizations, multiple factors are found critical, such as interpersonal competencies (e.g., sustainability, CE design) [98,103], organizational innovativeness [97], operational strategy in the production process [99], infrastructure management [99], skills and competencies managing internal and resources [97,99,103], consideration to financial aspects (e.g., cost competitiveness) [99,100], solid alignment to organization's ongoing strategy [99], the inclusion of strategic decision parameter such as net present value (NPV) [104], experimentation and prototype development [97], comprehension of the value of product/service value and its success criteria [99].Furthermore, the rate of increased recycled material has been given priority [104].To assess the (environmental) impact of business operation, particularly in product manufacturing, climate change (e.g., greenhouse gases (GHGs) emission)/environmental effects [100,103], application of impact assessment methodology (e.g., life cycle assessment-LCA) [106] and implementation of digital technologies (e.g., Internet of Things-IoT and Artificial intelligence-AI) [106] was emphasized.
To develop VP in CBM, assessing consumer-oriented value in products and services, some of the factors such as identification of customer interface/stakeholder need [97,99,100], requirement of high customer interest [99], consumer awareness/behavior/habits [105,[107][108][109] and method of consumers' payment/participating payment structure [105] were found critical.

Factors Related to Value Creation & Delivery
Value creation and delivery largely depend on internal and external activities to achieve specific goals and targets.Within the (internal) boundary of an organization, several factors were found critical on the issue, such as managerial practice and capability enhancement [110,111], organizational strategy (proactive/reactive) [109], consideration of internal and external contextual factors [103,112], fulfilling legal requirements [112], well-being of people, nature, and culture [110,113], understanding of monetary and non-monetary aspects of business [110], firm competitiveness and profitability [114], adoption of cost-competitive process [113], internalizing social, environmental, and territorial value [115], asset management [116], business model experimentation [7], building choice architecture [109], technology adoption [117], societal expectation/ambition [118], green and sustainable procurement [119], technological innovation [107], disruptive innovation [118], and corporate social responsibility application to entire network/suppliers [107,112].In the CBMI process, partnering with external partners and stakeholders eases the value-creation process.Several factors on this issue were mentioned, such as Ecosystem orchestration [111] and material and energy use through symbiosis [115].
Factors related to product-service system [119] in value creation and delivery are highly critical such as role of product design [7], buying second-hand or used items/reuse [108,119], durable product design [111], concurrent design of product and business model [103], adopting product life extension strategy [109,111,122], collection and product return management/product recirculation/reverse logistics [109,111,112,116,119], design and system thinking of the designers [103,111,117], environmental protection/benefits [109,121], product size [122] and, transportation type [112,122].For customers, value is created and delivered.Thus, several factors were highlighted, such as identification of the customer segment [7], interaction with them via the Internet [114], and improvement of communication medium with the customers (e.g., aggressive marketing/advertising strategies) [105,109].

Sustainability and Circularity in BMI
Regarding business ecosystem dynamics and innovation, Antikainen & Valkokari [123], along with Benz [124], emphasize the causes and trends that shape ecosystems and their impact on company operations.Comprehending this is essential for businesses seeking to adjust and prosper in evolving environmental circumstances.Additionally, the ability to engage in radical and disruptive innovation through entrepreneurship, as explored by Antikainen & Valkokari [123], Pieroni et al. [125], and Boldrini & Antheaume [126], is crucial for companies to remain competitive and adaptable to the changing ecosystem.
In business operations, the focus is increasingly on sustainability and circularity.Antikainen & Valkokari [123] highlighted the need to incorporate sustainability and circularity into corporate operations, stating that doing so is advantageous and essential for achieving lasting success.This is reinforced by the emphasis on circular product/service design by Benz [124] and Guldmann & Huulgaard [127], highlighting the significance of reconsidering product lifecycles and resource allocation.
Choosing sustainability strategies [127] and enhancing production and operational capabilities in material design and resource management [127,128] are crucial for businesses that adhere to sustainability and circular economy principles.These capabilities allow organizations to create new and improved product and service options that are both environmentally friendly and financially feasible.
Corporate social and environmental behavior [129] and adopting a technology-centered approach [124,125,129,130] are signs of a broader move towards responsible and innovative business practices.Performance evaluation, competence assessment, and capability assessment [131,132] are tools businesses can use to measure their progress in these areas, ensuring they meet their sustainability goals and maintain a competitive advantage.
Understanding sustainability and the circular economy is crucial for organizational learning and adaptation.Organizational change management, focusing on people and culture, is essential for driving sustainable change, as emphasized by various researchers [124,125,131,132].This stresses the importance of human resources in the process.Collaborating with internal and external stakeholders, as highlighted by Boldrini & Antheaume [126] and Guldmann & Huulgaard [127], emphasizes the significance of inclusive sustainability approaches that utilize a variety of viewpoints and skills to accomplish shared objectives.
Due to the significant influence of government regulation, it is crucial to ensure that corporate activities comply with regulatory requirements and utilize government backing for sustainability projects.As Benz [124] highlighted, the focus on customer satisfaction and transparency demonstrates the increasing need for ethical business practices and organizations to convey their sustainability initiatives to consumers.

Digitalization and Technologies
Researchers are interested in proposing and implementing state-of-the-art digital technologies for BMI.Technologies can be broadly classified as physical, digital, and biological, as observed from various international best practice case studies [133].In the collection of the articles, technologies, primarily digital technologies, were identified as critical framework components of the researchers.Furthermore, due to enhanced applications of the IoT and industrial automation, a large volume of data is being generated across the product lifecycle, a critical asset in the value creation in the product/service value chain.The articles are summarized in Table 1.The articles focused on using technologies and digitization in various CBMI spaces.https://www.hos.pub

Matrices and Assessment
Using the BMC, Sucozhañay et al. [145] presented a framework for understanding the CE based on four essential components: principles, drivers, stakeholders, and strategies.The evaluation of local study cases demonstrated that incorporating the sustainability approach rather than a systematic implementation of the CE leads to adopting circular business practices.Gathering data from secondary case studies, Rossi et al. [146] introduced an assessment tool that showed that in the shift to new business strategies, CE principles are expanded to cover the complete product lifecycle, from product design to product consumption.The authors used the tool to show how intellectual assets might aid in the circular economy through circular projects' planning, evaluation, and comparison.

Analyzing Papers on Frameworks for Business Model Adoption/Implementation
The authors within this research segment were mainly concerned with applying various types of technology in an organization, business ecosystem, product lifecycle management perspectives, product-service system, and brief assessment of CBM value dimensions and archetypes from the implementation/adoption perspective.This section summarized articles that focused on implementing CBM by developing various frameworks.In total, seven perspectives, namely, technological innovation, business ecosystem, product lifecycle management, product-service system, CBM classification, CBM value stream, and organizational capabilities and dynamics, were identified from the papers.Among the various categories, the last category received the most significant attention from the researchers.

Technological Innovation Perspectives
Table 2 summarizes articles associated with the technological innovation perspectives in CBM implementation.The articles were characterized according to the place where technological innovation could occur, their impacts, and related technologies.From the table, there are ample opportunities for research investigating the effect of technological innovation on ethical practice, eco-environmental and financial performance, and enhancement of dynamic capabilities of organizations.For example, prospects around production-specific technologies such as additive manufacturing (e.g., 3D printing) should be assessed more towards using materials from end-of-life resource recovery.Remanufacturing strategies could be effectively utilized, especially for automobile parts, building, and construction products.AI and mobile applications would also be particularly useful for sharing platforms (e.g., unsold food reselling) and product-as-a-service (e.g., cloud computing-based AI for predictive maintenance and real-time performance control) type BM.Ultimately, technological innovation should be focused on from the CE principle(s) perspective.

Business Ecosystem Perspectives
Implementing CBM at the business ecosystem level requires a comprehensive approach, as multiple academics emphasize.The main criteria consist of significant economic, social, and political transformations that impact laws, regulations, and consumer behaviors [18,159], as well as a deeper comprehension of the BMC building blocks (e.g., key partners, key resources, key activities, VP, customer segments, customer relationship, channels, cost structure, and revenue stream), especially those associated with value generation [160].Voluntarily implementing innovative sustainability strategies [161], coordinating networks [162], and fostering organizational learning [163] and knowledge management [163] are also essential.This is reinforced by the requirement for cooperation among many sectors, such as procurement and business models [164], and the establishment of co-design platforms that engage diverse stakeholders in the value chain [165].Furthermore, it is crucial to implement cross-sectoral policy interventions [166] and network orchestrators [167], explore alternate material development, and employ digitalization and climate change mitigation techniques [168].The interconnection of logistics infrastructure and services [169], along with the need for context-specific institutional elements [170] and modifications in law and corporate practices [171], highlights the extensive need for adopting CBM.
The effects of implementing CBMs in the ecosystem are significant and diverse.Researchers highlight the enhanced ability for innovation, collaboration, and engagement [159], which drives the shift towards a circular ecosystem [160] and the creation of sustainable business models that support the attainment of the Sustainable Development Goals (SDGs) [161].New CBMs [162] enhance resource efficiency [172], streamline procurement processes, and minimize waste in production [164].It also promotes extending the lifespan of products [166] and achieving circularity in the construction, operation, and disassembly stages at the system level [168].Improved material recycling, waste management [169], productivity at the company level [170], and the adoption of circular economy initiatives with stakeholders [171] have notable effects.Furthermore, adopting CBMs encourages innovation in CE and brings about socio-economic changes [173].It also enhances knowledge of CE principles, promotes transformative leadership [167], and creates new CBMs significantly shaped by government policies and technology implementation [18].Together, these effects help create a more sustainable and efficient company environment.

Product Lifecycle Management (PLM)
Sigüenza et al. [174] studied the appliance manufacturing industry, focusing on how innovation diffusion, product stock dynamics, and LCA might be used to monitor and evaluate items in the CE.Veleva & Bodkin [175] highlighted the significance of sustainable end-of-life (EoL) management in biotech equipment manufacture.They stressed the possibilities of reuse and remanufacturing, the value of online information sharing, and the heightened social responsibility awareness requirement.Mendoza et al. [176] examined the importance of CE strategies and CBM types in different stages of the product lifetime in the wind energy industry, highlighting the importance of long-life and future CBMs.Di Biccari et al. [177] studied the application of structure information modeling in the building and construction industry to promote circularity and manage life cycle costs.Siguenza et al. [178] studied the washing machine market and recommended implementing a pay-per-wash model and product leasing to improve material usage efficiency.Cholewa & Minh [179] discovered that PLM systems help enhance CE concepts in manufacturing by aiding product creation, promoting transparency, and maximizing value.

Product-service System (PSS)
PSS is a servitization-focused innovation and production approach in which value is created by switching from selling a product to providing comprehensive customer solutions.A general classification of the PSS system can be found in [180].
Sholihah et al. [181] examined strategic alignment, highlighting that it may not always correspond with corporate strategy and can be addressed through either a top-down or bottom-up approach.Aldieri et al. [182] highlighted the advantages for both businesses and customers, stressing the need for research and development in eco-innovation.They also emphasize the necessity of a transformation process to incorporate resource strategies into PSS business models.Bech et al. [183] discussed the need to quantify environmental potential and utilize LCA in the initial design phases to transition to the CE.D'Agostin et al. [184] pinpointed factors that influence adoption, such as technology significance and capacity assessment, as well as obstacles like PSS availability and understanding of pricing and consumption trends.Pieroni et al. [185] examined the possibilities for circularity in sustainability-oriented PSS BM, emphasizing key factors of superior customer value, economic growth, and resource decoupling.Holtström et al. [186] discussed the development of business models, highlighting obstacles such as technical platforms and distribution networks.They emphasize that sharing can help reduce the effects on production, consumption, and distribution.Borrello et al. [187] introduced the concept of "food-product-as-a-service", connecting food supply with food waste handling.Planing [188] discussed the transition process from result-oriented PSS to typical tangible item purchasing strategies.Hidalgo-Carvajal et al. [189] suggested a classification system and connections linking servitization with research, strategy, and sustainability sectors.Hernandez [190] analyzed internal and external factors, highlighting facilitators, including expertise in circular product design and innovative business strategies.

CBM Classification
Rosa et al. [42] found that triple-bottom-line benefits should be integrated when classifying CBM (e.g., recycling, product-oriented, use-oriented, and result-oriented PSSs) to realize CBM adoption benefits.In another study, Rosa et al. [191] found that key enabling technologies (KETs) are intertwined with the effective recovery of secondary resources.In that case, the suitability of CBM in PSS is critical.Focusing on archetypes and organizational performance, Karman [192] found that renewable resources, replacing the conventional business model's linear flow of resources, goods, and waste, were identified as critical factors for new business model patterns.On the other hand, Pieroni et al. [52] mentioned that existing archetypes have a reductionist mindset and pay little attention to the downstream value logic.The authors focused on archetype implementation in manufacturing.Han & Jin [193] found that cost and convenience for both businesses and consumers should be classified into loop-based BM.For identifying wastewater and regional food production system-focus BM opportunities, Al-Saidi et al. [194] mentioned that expanding municipal wastewater reuse alternatives and valorizing organic waste are two crucial circular economy approaches for the GCC's primary supply sector.From the morphological classification of CBM standpoint, Ludeke-Freund et al. [15] found that distinctive traits of elements/ design approaches were identified to provide a wide range of BM design options supporting the closing of resource flows.Guerra et al. [53] applied BM classification in the construction sector and suggested the Order of applications: 1st the automation and Software business category, the 2nd: reducing and recovering accounts, and the 3rd: reuse.

CBM Value Dimension for Implementation
The articles were characterized based on research focus, influential factors associated with CBM implementation, and specific criteria and types under the VP, VCD, and VC.

VP
Diaz Lopez et al. [195] focused on system adoption and degree of integration and found that resource efficiency measures (REMs) and business model changes were the critical factors that determined the market and behavioral barriers associated with the VP.However, the VP should have an economically viable process development process [196].Some authors mentioned the characteristics of VP in CBM, such as climate-friendly multiple usability [197] and time-variant product design [198].The importance of R-strategies (e.g., reduce, reuse, and recycle) was highlighted by Rodias et al. [199].The application of various tools and platforms, such as technoeconomic assessment and LCA [200], and "Circular Hub" [201] were highlighted.

VCD
Salvador et al. [202] emphasized the significance of strategic alliances and stakeholder participation in CBM, highlighting the crucial role of customer segments, supplier and customer relationships, and stakeholder cooperation.Sousa-Zomer et al. [203], Kvadsheim et al. [204] emphasized combining organizational activities and partnerships for implementing CBM.They highlighted the significance of Engineer-to-order (ETO) principles and dedication to circularity.Mogos et al. [201] talked about innovation in CBM with the help of stakeholders and university students.
De Angelis & Feola [205] utilized the ReSOLVE framework to analyze SME innovation in bio-based product creation, emphasizing the importance of executive positions and organizational procedures.Leder et al. [206], and Awasthi et al. [196] highlighted the importance of collaboration, technology, and waste utilization in creating value in bio-based business models.They differentiated between high-volume, low-value, and low-volume high-value waste for biorefineries.
de Carvalho Araújo et al. [207], as well as Awasthi et al. [200], examined technical elements of value chain design, emphasizing the significance of lifecycle impact hotspots, activity modifications, LCA as a design instrument, temperature management, and pollutant mitigation.Fraccascia el.[208] deliberated on inter-firm waste exchange within IS-based business models.
Uvarova et al. [209] concentrated on manufacturing high-value products, with a particular emphasis on EoL management and solutions such as downcycling, recycling, and upcycling.Diaz Lopez et al. [195] found obstacles in VCD, but Nyström et al. [198] proposed "Future Adaptive Design" for product-oriented companies to reduce business risks.
Bocken et al. [1] stressed the significance of visionary statements and goals in product design and business model strategies, focusing on value management, resource optimization, system effectiveness, and natural capital augmentation in SMEs' business model experimentation.

VC
The value capture dimension is loosely discussed in the identified papers.Bocken et al. [1] mentioned that VC can be understood from "Systems thinking" for decision-making and CE transition.Mogos et al. [201] mentioned new sales, long-term agreements, and product returns.Financial rewards and the cost of product innovation were identified as potential pathways by Nyström et al. [198].At the same time, Uvarova et al. [209] found that emerging, promising, and outstanding products have the highest opportunity of capturing value.

Organizational Capabilities and Dynamics
Shifting to a circular economy requires substantial organizational changes, including enhancing certain specificities and supporting dynamic transformations inside enterprises.This section analyzes the relevant literature, emphasizing the managerial competencies and dynamics necessary to implement CBMs successfully.

Fundamental Abilities for CBMs
Authors such as Reim et al. [210] emphasized the importance of a systemic viewpoint (i.e., system thinking) that considers the entire value chain and recognizes the interconnections among different elements in the circular system.Organizations can use this to pinpoint resource recovery opportunities and enhance material flows across the product life cycle.Network Orchestration requires collaboration and coordination with multiple parties.Hofmann [211] emphasized the importance of successfully coordinating internal and external networks within and across firms to enable information sharing, resource exchange, and collaborative problem-solving.Lopes de Sousa Jabbour et al. [212] highlighted the significance of dynamic skills in helping organizations adjust and evolve in reaction to changing market conditions and evolving CBM strategies.The qualities consist of continual learning, strategy renewal, and technology adaptation.Developing CBM design, implementation, and management competencies is essential for transparent resource management.As highlighted by Abdelmeguid, Afy-Shararah & Salonitis [23], transparent resource management promotes trust and accountability among internal and external stakeholders.

Building Circular Capabilities Strategies to Implement Changes
Various publications, such as Salvador et al. [213] and Lahti et al. [214], emphasized the crucial importance of top management support in promoting the adoption of CBM and allocating required resources.Leaders must advocate for change and establish a culture of sustainability inside the organization.Lopes de Sousa Jabbour [19] emphasized the significance of data gathering and exchange in ensuring the successful implementation of CBM.Organizations can use this to monitor material flows, track performance, and make well-informed decisions.Di Vaio et al. [215] stressed the need for process integration to optimize resource utilization and reduce waste generation.Lopes de Sousa Jabbour et al. [212] emphasized business model innovation as a crucial method for developing new VPs and facilitating circular practices.

Impacts on Organizational Dynamics
CBMs typically enhance resource management through waste reduction, efficient resource allocation, and support for resource recovery initiatives.This can reduce expenses and improve operational effectiveness [23,215].Partnering with suppliers through supply chain collaboration is essential for successful CBM deployment.Kelly et al. [216] emphasized that open communication and early supplier involvement in procurement processes are crucial for achieving resource efficiency and circularity in the supply chain.CBMs can significantly enhance social and environmental sustainability by lowering resource depletion, minimizing pollution, and encouraging responsible production and consumption habits [217,218].This can bolster the company's reputation, appeal to eco-conscious consumers, and boost stakeholder participation.

Analyzing Papers on Circular Supply Chain
Very few articles have been published on the supply chain issue.The data showed that closedloop supply chain management focusing on CBM, circularity, and sustainability will be the next giant research hotspot.Digitalization and PLM were discussed segmentally.However, holistic ecosystem orchestration and process harmonization would require a holistic understanding of PLM with digital technology applications, which will also be a future research area.Based on the adoption factors around 1) sustainability and circularity principles, 2) strategic and organizational performance, 3) CBM value streams, 4) digitalization and product lifecycle management, and 5) product service systems are summarized in Table 3.There could be two loops in a circular supply chain: an open loop and a closed-loop supply chain.The table shows that digitalization, PLM thinking, and practice are crucial for various CBM developments.This same approach was used in the PSS and CBM value creation at the whole value chain level.These research areas require further attention.

Discussion
Examining CBMI, its implementation, and its incorporation into circular supply chains demonstrates a complex area of challenges, opportunities, and strategic factors crucial for moving towards a more sustainable circular economy.Studying CBMI frameworks highlights the varied and intricate nature of the CBM research field, influenced by industry-specific needs, organizational setups, and the incorporation of cutting-edge technologies.This diversity illustrates the flexibility of CBMs but also reveals the lack of a cohesive framework, indicating a notable gap in the literature that future research could seek to address.
Moreover, categorizing CBMs and analyzing value dimensions offer a structured method for comprehending and executing circular strategies.Transitioning to a circular economy requires substantial organizational changes, such as adopting systemic thinking, orchestrating networks [111], and developing circular capabilities.Achieving circularity via CBM is a thorough process that necessitates aligning several elements of the company model and the broader business ecosystem.
The innovation process in CBMI focuses on developing R-strategies [199] and ReSOLVE actions [17][18][19][20] to prioritize sustainability and circularity.This involves strategic collaborations and adopting service-oriented technologies to address organizational inertia and market resistance [59].Identifying bottlenecks and inefficiencies across the product chain [133] could be the starting point.
Transitioning to circular supply chains is crucial for implementing CBMs, and a thorough grasp of PLM and digital technology is required.Adopting CBMs and altering supply chains present complex problems that encompass operational, strategic, and technological changes.Implementing CBM inside organizations and at the business ecosystem level emphasizes the need for a comprehensive approach that includes technical breakthroughs, organizational reforms, and strategic shifts to support this transformation.Identifying open and closed loops in the circular supply chain highlights the importance of advanced solutions for managing various product flows.This indicates that digitalization and PLM could improve circularity and sustainability.
From a methodological standpoint, material use, material intake/disposal and recirculation, organizational types, application of CE principles and R-strategies, and prosperity of the business model in a specific cycle are the main determining factors for CBM archetypes and classification, as seen in Section 4.1.1.Integrating the material-water-energy nexus could be a critical starting point in this instance.
The reviewed studies explore the broader effects of CBM on organizational dynamics, stakeholder involvement, sustainability outcomes, and potentially the SDGs.Technological innovation, especially in preventive maintenance, additive manufacturing, and AI, is emphasized as a driver for sustainable production and consumption practices.Yet, incorporating these technologies to enhance operational efficiency and encourage circularity comes with distinct problems.The reviewed articles also address the necessity of PSS in transitioning to servitization and the significance of comprehending customer needs and promoting a sustainable culture.Organizations should have specific skills and competencies to address product innovation and BMI.The impact of technology, certification, or increased branding (i.e., a product made with recycled material, better for the environment) should be assessed considering market barriers and specific customer benefits.Customers might adopt perceived product return strategies using innovative and effective communication strategies, providing scope for subsequent product use cycles and business opportunities, or effective EoL management.All products will eventually reach EoL and are destined for recycling, closing the loop resource strategy.
Based on the content of this review article, a conceptual framework can be developed connecting CBMI, CBM adoption/implementation, and circular supply chain about developing circular competencies by interconnecting various vital elements of CBM, which is shown in Figure 10.To make a CBM successful, initiatives should be taken from a supply chain level.As seen https://www.hos.pubBased on the review, this article defined a circular business model as a business model that fundamentally applies one or more of the principles of CE at various product/service/material lifecycle stages, for which sustainability-focused technological innovation, collaboration among business ecosystem partners, and enhanced dynamic capabilities of any organization are prerequisites.

Research Gaps and Future Research Directions
Based on the review performed in this study, several research gaps were identified which should be addressed in future research.
• More research should be undertaken to explore the integration of Industry 4.0 across operational activities and eco-design practices.In this connection, ample opportunity exists to investigate the impact of technology improvements on the enhanced customer experience, organizational performance, and supply chain sustainability.• The role of PLM in environmental sustainability has been researched minimally, which should be explored more.It is seen from the literature that although loosely connected, digital platforms and data are related to PLM.There is a need to develop a digital transformation standard for data management and security.Research on process optimization and predictive analytics for resource management should be prioritized.For increased transparency and efficiency, the application of AI, IoT, and blockchain should be more for circular supply chains.• There is also a need for research investigating the applicability of CBM archetypes and businesses' understanding of knowledge and awareness around it for those who tend to adopt CBM (i.e., companies previously running on LBM).This would solidify both current intellectual scholarship of CBM archetypes and develop a new classification framework that the businesses can quickly select according to their existing operation based on CBM value dimensions, mainly value creation, and VP.
• The literature does not exclusively investigate customer interface and user experience in circular products from the CBM perspective.Some studies consider the theory of planned behavior (TPB) for PSS.Still, there are ample opportunities to understand customer needs and requirements for circular products and the impact of technology in the customerfocused CBM innovation process.• The holistic benefits of the PSS would only be realized if appropriate impact assessment methods, such as LCA, and flow-based resource efficiency measures, such as material flow analysis, could be integrated considering PLM.Evaluating the current strategy for product development and including CE principles would provide more significant opportunities for environmental and social benefits.• Nevertheless, the transition from LBM to CBM is only possible when the external and organizational internal ecosystems (e.g., various departments in organizations) collectively pursue the vision of CE principles.For instance, further research is required on how partner organizations adopt CE principles and sustainability and include them in their CBM.• The academic literature less discussed value capture-related perspectives under the implementation/adoption frameworks, as seen in Section 4.2.6.Value capture could take different forms depending on the CBM type and the business' operational cycle.From the sustainability perspective, value capture-related components such as the social contribution of the business model and the number of employees could be included or investigated.

Conclusions
The CBM is an emerging research area within the circular economy context as an enabling element.This study systematically assessed 256 papers on CBM frameworks (i.e., by distinguishing the difference between CBM frameworks and CE frameworks) published in international peer-reviewed journals using content analysis methodology.Results of the study show that CBMframework-related studies can broadly encompass three directions: BMI frameworks, business model adoption/implementation frameworks, and circular supply chains.Under the BMI frameworks, CBM archetypes and classification, innovation process, business model experimentation, CBM value dimensions/stream (e.g., value proposition, value creation, and delivery, value capture), sustainability and circularity, digitalization and technologies, metrics, and assessment were the core components.On the other hand, technological innovation, business ecosystem, product lifecycle management, product-service system, CBM value dimension and classification in practice (from the implementation process perspective), and organizational dynamics are discussed under the business model adoption/implementation perspective.Various adoption factors were identified from the circular supply chain perspective, aligning sustainability and circularity principles, strategic organizational performance, digitalization and product lifecycle management, product-service systems, and CBM value streams.Innovation process, CBM value stream perspectives, organizational capabilities, and dynamics were well-discussed topics around CBM frameworks.The thorough analysis in this review shows that incorporating CBM is becoming a significant step towards sustainability and economic resilience for sectors such as electrical and electronics, renewable energy, building and construction, and fashion and textile.This paper stresses the need for a more unified comprehension of CBMs, especially regarding innovation processes, implementation techniques, and the overall influence on the circular economy.
The conceptual framework developed in this study is not just a theoretical construct but a practical tool for integrating scattered studies on CBMs.It highlights the importance of technical innovation, collaboration across business ecosystems, and organizational competencies in facilitating the shift toward circularity and developing circular competencies.The analysis concludes that developing CBMs requires a multi-faceted strategy emphasizing innovation, adoption, and integration within circular supply chains to establish sustainable and regenerative economic systems.The study also identifies key research directions that can foster CBM innovation and implementation in areas such as technology deployment, customer interface, CBM archetypes, ecosystem transition, and assessment of the social contribution of CBM.This study provides a valuable guide for policymakers, business executives, and academics to enhance their comprehension and application of CBMs, supporting sustainability objectives and circular economy concepts.
This research also has limitations.The study predominantly focuses on CBM frameworks, which can be extended to broader aspects of CBM.It could provide a more holistic overview of the CBM research field, connecting various core concepts.The collected materials for this review were considered until June 2022, a limitation identified in this paper.Furthermore, developing a framework (e.g., conceptual, theoretical, analytical) may also provide a fresh new perspective.Text and qualitative data analysis are challenging when the papers are from various disciplines, which might restrict idea generation, conceptual framework development, and application across multiple disciplines.Future researchers should take this matter and develop a new methodological framework for text data analysis.The framework presented in this article is a preliminary representation integrating all associated topics and subtopics that came under CBM-frameworkrelated studies.The topic discussed could generate an individual conceptual framework highlighting the underpinning of the related issues (e.g., initiatives enhancing organizational dynamics to have CBM-focused outcomes).The complexity of integrating factors should be explored in the future.

Funding
The second author acknowledges research-related support from the Victorian State Government through the Victorian Higher Education State Investment Fund (VHESIF).

Figure 2 .
Figure 2. Country of publications in CBM research areas.

Figure 3 .
Figure 3. Types of frameworks that emerged in the articles.

Figure 4 .
Figure 4. Distribution of main categories of the articles for the review.

Figure 5 .
Figure 5. Categories and sub-categories under the main subject areas of the articles.

Figure 6 .
Figure 6. Background building blocks of CBM archetypes and classification (Source: Authors' development based on the reviewed papers).

Figure 9 .
Figure 9. Summary of the business model experimentation studies.

Figure 10 .
Figure 10.The conceptual framework for the development of circular competencies for CBM innovation and implementation (Source: Authors' development).from Sections 4.1.7 and 4.2.1, technological innovation and its application in CBMI and the adoption process play a critical role.Strategic collaboration with stakeholder engagement and technology deployment jointly addresses organizational barriers and obstacles and creates customer-focused CBM value stream development opportunities.This framework might help organizations identify an interrelation between various components of CBM and develop their circular competencies in developing a CBM, starting from innovation to circular supply chain integration and implementation mechanisms in business organizations.Based on the review, this article defined a circular business model as a business model that fundamentally applies one or more of the principles of CE at various product/service/material lifecycle stages, for which sustainability-focused technological innovation, collaboration among business ecosystem partners, and enhanced dynamic capabilities of any organization are prerequisites.

Table 1 .
Type of technologies in the specific innovation process.

Table 2 .
Summary of areas of technological innovation, their impacts, and specific digital technologies.

Table 3 .
Factors affecting the circular supply chain for CBM implementation. https://www.hos.pub