Challenges of Engineering Skillsets Essential for Driving Circularity of Smart Cities

Abstract

This study aims to define specific transferable engineering capabilities needed for the implementation (design and practices) of circular economy (CE) within a smart city setting. We conducted a critical literature review of over 100 studies on the core values of CE and smart cities to investigate the knowledge gap in this topic and understand what specific skillset is employed by industry experts that can be harnessed on a wider scale, which can allow for the optimization of CE. There is a lack of research on the skillsets needed to implement a circular economy in any setting, and there are very few studies on circularity practices in a smart city setting. Primary data collection allows us to bridge this knowledge gap, yielding new findings that do not already exist concerning the skillset employed by experts in the field, which can positively impact the smart city settings in which a circular economy is implemented. We conducted a qualitative analysis based on expert interviews of 21 participants who have experience in the circular economy. This information will benefit the industry by informing businesses and councils about the key skillsets and capabilities to look out for when employing people to implement any aspect of circular practices in a smart city setting, with an emphasis on enhancing efficiency, achieving deliverables, and thinking systemically to address complex challenges they may face during the implementation. We also investigated the implementation of CE in smart cities to provide a well-rounded view of the different achievements and challenges faced during the process. This mainly focuses on the work of governance in smart circular cities, a factor that has many important implications and externalities in different sectors. This study describes the methodology adopted to formulate a detailed questionnaire for expert interviews with respect to the skill gap and capabilities necessary for working in the industry, the results of which aid discussions regarding the different challenges faced in CE implementation. Our findings reveal that background knowledge in engineering and sustainability is the most ‘highly critical’ hard skill according to the experts, while communication and stakeholder engagement are the essential soft skills required to ensure the success of a circular economy within smart city settings.

1. Introduction

‘Smart cities’ have a famously ambiguous definition. There is no right or wrong solution, and many different researchers have attempted to craft their own definitions for smart cities based on several socio-economic and technical factors. The essence of smart cities is that they employ digital technologies such as the ‘Internet of Things’, which allows data to be analyzed and optimized for the system to make better informed operational decisions moving forward, with the purpose of improving several aspects of the city, which relates to the goal of being more sustainable. For example, Barcelona is a smart city; it uses information and communication technologies and governance in the economy and environment for effective urban management and is now considered a European success story of urban development [1,2]. Other cities employ such technologies and practices with the aim of replicating the successes of Barcelona, which is ranked as one of the top four best cities in Europe to start new businesses. However, employing smart technologies alone does not guarantee sustainable results. For a smart city to operate in such a way that sustainability goals are met, a circular economy (initiatives, technologies, and practices) must be introduced.

A circular economy (CE) is an economic system aimed at eliminating waste and pushing the regenerative use of resources [3,4]. The EU Circular Economy Action Plan is a manifesto promoted by the EU to prioritize circular processes and sustainable consumption to circulate resources, which reduces the demand for raw materials [5]. There are many different thought processes that support the implementation of a CE. Primarily, there is the idea that by increasing a product’s lifespan, people will need to buy the item less often, or if the item is recycled, then it means that the commodities and natural resources will have to be imported and used less often. However, looking at the bigger picture, it has much more to offer, ranging from new job opportunities to the eventual reversal of biodiversity loss [6], leading to positive impacts on climate change. Extending a product’s lifespan has endless benefits, such as better value for the customer (due to lower costs and because the customer will be pleased knowing that they are consciously aiming to reduce waste) as well as an unprecedented positive impact on the sustainability aims of smart cities. The issue, however, is that the current level of circularity in the EU is not sufficient to offer the profound, visible, and immediate benefits listed above, with the EU’s circularity rate, i.e., the share of material resources coming from recycled waste materials, being 11.7% in 2021 [7].

Based on the critical literature review of 100+ relevant articles available on Scopus and Google Scholar databases [8], the knowledge gap analysis reveals that no articles in the literature focused on or discussed the implementation of CE within smart city settings, particularly regarding engineering skillsets and transferable capabilities or even the hard and soft skills needed to facilitate CE implementation. The keywords used for the literature review include (i) circular economy, (ii) skill, (iii) capability, (iv) smart city, and (v) Internet of Things. Boolean operators based on the words "AND" and "OR" were used in the literature search on Google Scholar (advanced search option) and Scopus. The search for the most relevant literature (overlapping with at least two keywords) resulted in over 100 articles. However, our critical review reveals the acute shortage of research on engineering skills and capability required to implement circular practices in smart cities. This has led to the following research question: what are the critical skills required to generate growth in the adoption of a circular economy for smart cities? Therefore, this study aims to investigate the fundamental skills and education needed by industry practitioners to enact circular and smart cities. Using a rigorous questionnaire that concerns the expert’s hard and soft skills, language proficiency, and ability to encounter challenges and implement security and privacy measures, there is an opportunity to maximize the impact of CE on smart cities, aiming to increase circularity rates and, in turn, offer greater opportunity for innovation and the achievement of smart city sustainability goals. Expert interviews were conducted to derive new insights. Such studies are relatively unprecedented in Europe, and the European Commission has recently funded an EU-wide action called ‘CircularB’ to systemically assess the challenges and barriers to circular economy implementation. By addressing the research question in this study, we can streamline our efforts to develop tools and educational programs that can overcome the challenges and barriers faced by industries. The outcome of this study will improve the adoption of CE measures in smart cities.

2. State-of-the-Art Review

Europe’s CircularB Action has already identified the severe lack of circular economy implementation in built environments across Europe. In particular, existing building stocks face the most critical challenges. Smart buildings located in smart cities have been around for many decades (considered as an existing building stock), but it can be observed that many of them have not used circular economy practices to improve their sustainability. This evidence underpins our research question and supports the rationale for conducting this study. In our study, we will categorize the relevant studies into three themes: (i) smart cities; (ii) circular economy (CE); and (iii) the implementation of CE in smart cities. The literature review revealed a shortage of research and insights into CE implementation within smart cities, as detailed below.

2.1. Smart Cities

2.1.1. Internet of Things (IoT)

The Internet of Things (IoT) is a technological practice, a system that has resulted from the evolution of conventional networks and enables quick and efficient decisions. It entails a large number of sensing devices that are connected to each other [9]. These devices share and analyze data and communicate through WIFI, Bluetooth, and other means to make an informed decision; in our case, the decisions involve the operation of a smart city that is sustainable, has low emissions, and enhances the quality of services for its citizens [9]. The idea is that there is minimal human interaction when decisions are made this way, which leaves out any risk of corruption or human error, ensuring that all decisions made are backed by data to ensure the best possible outcome with respect to a smart city’s sustainable development goals.

Although there are endless facts and data that are used by IoT technology in smart city decision-making, there are also drawbacks that must be considered. Ethical concerns have been raised about the General Data Protection Regulation (GDPR), security and data privacy breaches [10], and unauthorized access to connected devices; so, ethics play a big role when businesses decide to employ this technology in any capacity, with the aim of improving energy efficiency or reducing waste. Based on this, we included a key question in the questionnaire sent to industry experts: “How are privacy and security concerns due to smart city technologies in your work addressed?” Insights derived from this question will help improve our understanding of the precautions taken to mitigate and prevent these issues and will indicate other potential skills suggested by the experts, such as critical thinking, computing and software proficiency, and the indication of a growth mindset.

The Internet of Things is an ‘architecture’, a layered model format carefully planned by architects, with specific capabilities involving technical expertise, as shown in Figure 1. The main aim of this research is to identify the engineering capabilities and transferable skills needed to implement CE in smart cities in a way that maximizes its potential, and it has already been suggested that architects should begin to work on a new IoT framework that can optimize functionality, capabilities, and security. However, this must be performed in a way that does not cause fragmentation (disconnection of some parts of the Internet of Things from others) [11]. Studying the capabilities of industry experts may indicate the skills required to implement a revised IoT architecture that can maximize data analysis and outputs.

2.1.2. Systematic Perspectives of Smart Cities

The need for smart cities has never been questioned. A substantial portion of the world’s resources is utilized by cities; in fact, 75% of the total energy is consumed by cities [12]. This perpetual energy consumption generates nearly 80% of greenhouse gases, which have adverse effects on the environment [13]. This huge consumption, when managed incorrectly, can have profound adverse effects on the environment, with many expert sources predicting that as early as 2030, the damage caused by carbon dioxide emissions will be irreversible [14], which means that there will be adverse effects on the Earth’s temperature in the future. Given that cities are responsible for 75% of global CO₂ emissions [15], it is imperative that CE is implemented in the correct way to combat this issue effectively.

Governments are promoting the ‘smart city’ solution, understanding that investments in human capital, modern ICT infrastructure, and sustainable growth are key to a functional smart city, of which all aspects can be achieved through participatory governance [16]. Section 2.3.2 provides deeper insights into governance, which is a set of policies, regulations, and institutional frameworks that guide and influence the transition to a more sustainable setup. This can include promoting social action and manifestos (such as Reduce, Reuse, and Recycle), setting quantifiable goals such as emissions caps and net zero targets for corporations, and, most importantly, adopting the ‘Internet of Things’ system, outlined in Section 2.1.1.

Several studies examining all socio-economic and technological aspects show that smart cities are more effective if their innovation potential and knowledge processes are at the highest standard possible [17]. The appropriate technology and infrastructure must be in place to synthesize and quantify the data for some purpose, to make the correct informed decisions based on the context, and to improve efficiency and, in turn, sustainability and quality of life [18]. To ensure that the most innovative technologies are in place and are synthesizing data, it is imperative that the people involved in its transition, design, and installation are knowledgeable about circularity practices and possess the correct engineering skillsets. This further reinforces the importance of this research on this topic.

The existing research on smart cities is insufficient as it does not focus on the real-life aspects of the implementation of smart technologies. The bulk of the research has been performed by researchers who have never implemented circularity technologies and, therefore, do not understand the different complex challenges faced in its implementation; perhaps, they also do not understand the behaviors of the public, who will be affected by the practices. The aspects of smart cities stretch far beyond smart technologies. Certain skillsets employed by experts in the field would lead to positive developments, as stated before, being transferable across all aspects of the smart city, ranging from IoT technologies to circularity schemes.

2.2. Circular Economy (CE)

2.2.1. Definition of Circular Economy

A circular economy is an economic system aimed at eliminating waste and the use of additional resources by keeping recycled materials in the economy for as long as possible, as illustrated in Figure 2. CE is ‘a framework, which involves transforming how we manage resources, how we make and use products, and what we do with the materials afterwards’ [6]. There are many different thought processes that support the implementation of the circular economy. There is the idea that by increasing a product’s lifespan, people will need to buy the item less often, or if the item is recycled, then it means that the commodities and natural resources will have to be imported and used less often. However, in the grand scheme of things, it has much more potential, in particular, the sustainability advantages of CE being implemented correctly in a smart city setting, which is the primary focus of this study. The challenge of this study is to understand why circularity ratings are so low, especially in Europe, and to suggest the steps that can be taken to improve circularity in smart cities using industry expert questionnaires to understand the human factors that influence the efficiency of smart cities.

2.2.2. State of Practice of Circular Economy

In practice, there will be numerous job openings in a new sector, ranging from warehouse and floor workers to management and corporate roles. For instance, the analysis of CE-related sectors shows that Britain could have over 200,000 gross jobs created by the year 2030 [19]. CE will range from smaller day-to-day items to transport modes and potentially buildings; so, the benefits will range from more affordable and sustainable transport (as most of, if not all, methods of transport will be derived from recycled materials) and potentially cheaper construction costs as buildings will be reviewed (potentially with BIM, see Section 4 Results), aiming to reuse as much material as possible in renovations and new buildings.

CE can reduce waste and create more sustainable habits and business models [20] via the revised recycling scheme labeled as the eight Rs (refuse, reduce, reuse, refill, repair, regift, recycle, and repeat [21]) and by extending the lifecycle of products [22], which have several positive impacts on a large scale. Extending the lifespan of products results in less raw materials (and water + energy) entering the economy initially as fewer new items are being manufactured; it means that products will become cheaper as more second-hand/refurbished products will become available and that less greenhouse gas emissions are released as transportation and production are reduced.

2.2.3. Development of Circular Economy in a European Context

In 2020, the EU adopted a new plan called the Circular Economy Action Plan (CEAP), part of the European Green Deal, promoting circular processes and sustainable consumption to keep resources recirculating in the EU for as long as it is sustainable [5]. However, it is apparent that further development is needed due to deficiencies in the supply of standards, databases, or tools for the classification and monitoring of building circularity [23], which is the work undertaken by COST Actions CA21103 CircularB and partly by CA22124 ECO4All. The CircularB initiative consists of four working groups of esteemed researchers and construction industry professionals who aim to develop a common international framework for circularity rating, all harnessing their engineering skillsets in different interdisciplinary areas of research to bring together a framework based on several key performance indicators. The skillsets harnessed by these industry experts are vital as eventually, the framework in place will influence industries in smart cities to implement more circularity practices and operate in an innovative way in the future. Obtaining as many results as possible from the CircularB network would be ideal as there are few qualified practitioners to answer this study’s questionnaire, and if all practitioners implementing CE in a smart city setting also harnessed these skills, the development of smart cities would surge.

2.3. Implementation of Circular Economy (CE) for Smart Cities

2.3.1. Challenges of CE Implementation

Three of the biggest struggles in implementing a CE are a lack of financial support from authorities, a lack of long-term strategic goals, and a lack of CE awareness [24]. Finances are often a concern regarding major government-backed infrastructure or schemes. Some schemes can be restrictive. For instance, historically, when governments have enforced rules that can restrict or inconvenience the public, they are often met with backlash, e.g., people protesting against the expansion of the £12.50 ULEZ charge in London [25], which means that people with cars who did not qualify would have to pay a daily charge to drive through some areas in London [26]. However, when gauging the long-term savings potential of the implementation of CE in smart cities, the immense number of positive impacts it would have in day-to-day life for the public is apparent, namely, longer product lifetimes, which in turn lower environmental impacts [27] and costs. There would be little friction from the public due to these benefits and because of people’s guilty conscience, which tells them that they should live in a more sustainable and green manner; there is evidence that guilt and pride influence decisions to buy ethical and sustainable products [28].

There is a small chance of friction from individuals within the government themselves. The technological impacts have the potential to be highly beneficial, not only due to the extended life, making it more likely that people will be connected to the internet, which will vastly improve their quality of life, but also because different businesses will begin to implement more smart technology if they are guaranteed longevity (better value for money). The technology will also reduce the company’s carbon footprint, which is often desired and in line with its business goals. On the other hand, it is allegedly in a politician’s best interests to maximize profits for their own benefit (as well as that of their friends and ‘donors’ [29]) rather than save the average consumer money, which makes sense as more profits means better business performance for production companies, meaning that they receive more corporation tax; such CE will results in a significant reduction in the sales of new components and raw materials [30], which means less profits will be made, and the government will receive less tax.

Furthermore, the IoT, a context-aware network that connects a large number of sensors and devices, with the aim of sharing data and making informed decisions to positively impact the business, can be utilized. This is a huge step towards making the right business decisions to operate in a sustainable manner, and if most businesses in a city decide to implement this technology, it would result in major decreases in energy consumption and greenhouse gases such as CO₂ (over 2.0 Gt of CO₂ emissions reduced in the energy sector by 2020 [31]) and would kickstart the process of reversing the effects of years of pollution. Although there are great benefits for businesses wanting to save money and act in a greener way, it would lead to fewer profits for the government, which prevents companies from having free rein over the implementation and could potentially result in implementation with government regulation and governance. However, if there is motivation, such as a council aiming to narrow their emission gap and contribute to sustainability, especially that of supplier companies, there would be no reason for them to oppose the implementation of circularity [32].

The skills and capabilities of those implementing CE are the main factors in approaching and solving the challenges of a lack of long-term strategic goals and a lack of CE awareness.

2.3.2. Governance of Circular Economy in Smart Cities

Governance connects the key categories of smart transition through policies, regulations, and institutional frameworks that guide and influence the transition to a more sustainable and circular way of managing resources and materials. Figure 3 displays a way of envisioning the different modes of governance and how they can ensure all aspects of a smart city work together to achieve sustainability [32]. These policies, regulations, and institutional frameworks all play a huge role in the implementation and transitions involved as they quantify the aim; quotas, goals, business models, and incentives can be set, which will encourage businesses to adopt a more circular practice, but it also means that governments can enforce these quotas and penalize businesses that choose not to change their operations (such as the emission penalties in China), with the aim of implementing circularity practices. Such policies should be considered in Europe, with the aim of increasing the circularity rate, as it was found in China that the policy had a significant greenhouse gas reduction effect, specifically on industrial SO₂ emissions [33]. These policies would have to be drafted, proposed, and implemented to be as impactful as possible; so, research and communication skillsets must be utilized between the government and all stakeholders, once more emphasizing the importance of this study, which aims to find the optimal skillset required to implement CE to the best possible standard.

From Figure 3, it can be observed that governance branches into three different sub-categories: relationality (People), spatiality (Place), and digitality (Technology). Relationality is a mode of governance concerning relationships: relational responsibility building through transformative communication [34]. This is quite a broad mode when considering CE; however, it mainly includes having facilities in place to educate citizens on behaviors that promote circularity practices and to reward people who make changes to act in a more sustainable manner. It also potentially makes it easier/cheaper for people to start up a small business in the CE field to accelerate the growth of the market. This also relates to engineering capabilities and transferable skills. One of the biggest challenges of CE implementation is a lack of social inclusion and participation [35]. Utilizing relationality, the people in charge of the educational facilities will pass on behaviors and advice to the public. This means that if the people who are teaching and informing others have certain skills and behaviors, we will eventually see these behaviors being displayed, and therefore, it is important that people with the correct skillsets oversee the implementation of CE.

Spatially, it is a government’s ability to promote sustainable infrastructure. “Spatiality as an essential aspect of ‘the urban’ has a significant role in anchoring circularity through designated areas or enclaves that can be used in scaling-up CE solutions.” [32]. By optimizing a smart city for circularity practice, CE activities will become more efficient; for example, having sufficient recycling facilities in place will streamline the process, and using land sustainably and having sustainable transport options (including the promotion of cycling lanes) will make it easier for people to make life choices with CE in mind.

Digitality is the mode of governance that relates to the optimization of technology, with the aim of making CE more accessible and integrated with day-to-day life, pertaining to the question of how the city government utilizes new technologies to promote CE [32]. For example, the government may decide to promote the ‘Internet of Things’ technologies in schemes or incentives, making it easier and cheaper for businesses to set up the technology, or maybe the government could subsidize certain software that could be used to make more streamlined and energy-efficient business decisions. It also means that the government could introduce more strict regulations on new technologies implemented, like a cap on energy usage and carbon emissions and, potentially, new guidelines on the disposal of products that have reached the end of their lives. All these steps are controlled by the government (usually in association with innovative and skilled engineers) in order to promote CE in smart cities.

Governance is a key factor in the inclusion of engineering skillsets in CE implementation in smart cities; such practices, including schemes and education, must be collaboratively researched, drawn up, and delivered by engineers. Digitality requires a particular software and computing-based engineering skillset to make the technology operational and to continually maintain and update the systems to create a smart system that is as energy-efficient and decarbonized as possible.

2.3.3. Impacts: Jobs, Environment, and Ethics

Circular economy, the practice of extending a product’s regenerative life cycle via means such as the eight or ten Rs and other government schemes, reducing the need to import raw materials, means that smart city goals such as a prospering economy and improved environmental aspects will be achieved more easily by reducing the use of natural resources and enhancing knowledge about its implementation [22]. The positive impacts on the environment are endless, ranging from lower emissions to better land use, ‘deconstruction’, and the reuse of building materials for a less destructive impact on the urban environment [36].

Advantages can come from extending a product’s life for a much longer period, such as better value for the customer (due to lower costs and because the customer will be pleased knowing that they are consciously prioritizing waste reduction and management), and it will have an unprecedented positive impact on the aims and tasks of smart city authorities [37], i.e., reducing manufacturing emissions and other deliverables. For instance, if most manufactured items that are used daily in cities, ranging from cars and bikes to coffee cups and water bottles, had their lifecycles extended, it could result in great externalities, such as improved well-being (human health and state of mind [38]) since more people would have access to different transport modes and due to cheaper day-to-day costs, coupled with the peace of mind obtained from the fact that they are choosing to make changes to live more sustainably. It would also have the potential to create many jobs in this sector, ranging from project and process management to marketing and warehouse workers, who will have jobs such as recycling processors or machine operators.

2.4. Knowledge Gap Analysis

To address our research question (which engineering and technical skillsets are needed by industries to implement circular economy practices in a smart city setting?), we delve into the literature to define the limitations, scopes, research methods, assumptions, system boundaries, and stakeholders. This was conducted to serve our research goal and help us to design the questions for industry experts.

Evidently, no research exists on the technical challenge related to engineering skillsets required to implement CE and practices in a smart city setting, with the aim of making the system as efficient and innovative as possible; so, there was a knowledge gap in the research. Ranging from soft skills concerning communication, management, and professionalism to hard skills such as computer program proficiency and proficiency in several languages, skillsets cover a broad spectrum in engineering, which is why they are often unheeded when considering the implementation of new technologies and systems and when taking approaches to address the main challenges of CE implementation.

To identify the engineering skillsets that are needed to not only implement CE but also to maximize the efficiency of the system, with the aim of achieving a decarbonized system, the focus of this study was targeted at industry experts, i.e., individuals who have worked in sustainability and on circularity developments in a smart city setting. This was performed using an ethically reviewed questionnaire to outline the skillsets needed to work in the field, along with finding out additional details about the expert’s job roles and responsibilities. The details of the questionnaire are outlined in Section 3.1.2. The implications of this oversight will often result in impacted project successes as it has been found that a worker’s personal competencies (such as skills, training, knowledge, etc.) have a direct influence on the success of the project [39] and its deliverables, leading to a missed opportunity to implement CE and its technologies at the highest standard possible. Our review also found that qualitative research using the semi-structured interview method is widely used to address the topic of our research question.

The importance of this study is vital. The built environment has never been smarter, with more smart technologies harnessing the IoT than ever before to make informed decisions to help minimize energy consumption [40]; so, there is great potential for implementing CE practices to a high standard.

3. Materials and Methods

Our study was predominantly inspired by CircularB’s expert group meetings. The initial insight was derived from expert meetings. Then, our research question was formulated with the knowledge gap analysis. In this study, a qualitative research method (using snowballing expert interviews) was adopted. We first identified the data and insights related to the research question. The insights helped us formulate the questionnaires or open-ended questions used to interview industry experts and stakeholders. Qualitative analysis was used to develop aggregate understandings about the trends, priorities, and significance of engineering skills and education underpinning the factors critical to overcoming any challenge and barrier to circular economy implementation in smart cities.

3.1. Data

The method used to obtain primary data for this research is rigorous. The participant sample is an array of CircularB working group participants, professors, workers, industry professionals, and researchers with knowledge of CE and circularity implementation. This means that the results were not skewed because all participants were knowledgeable about the subject at hand and that all engineering skills and capabilities proposed will be confirmative and relevant to circularity implementation. The expert interviews were conducted in compliance with GDPR regulations and with signed consent forms. The questionnaire was subjected to a rigorous ethical review process as part of the project proposal stage to ensure that all data obtained would be used in an ethical manner and to outline how to eliminate any ethical concerns.

3.1.1. Research Data Collection

There is no previous research on the engineering skillset needed to work in the field of circularity implementation in a smart city setting. Therefore, primary data must be obtained using interviews. We formulated a questionnaire that was subjected to a full ethical review to gain background information on the industry experts, such as their qualifications and experience, the biggest challenges they have faced, how privacy and security concerns are addressed, and the specific hard and soft skills they need to perform their work.

One participant interviewed was the Head of Innovation and Partnerships in the UoB estates office, a participant heavily involved in the university’s project with SIEMENS [41] in a strategic partnership to create the ‘smartest’ campus in the world. This scheme is an implementation of circular technologies across the campus buildings, capturing data from the estates’ infrastructure and energy plants and using it for innovation, R&D activities, and teaching [41]. Because the participant is so heavily involved in the implementation, they were an ideal subject for the research. The bulk of the participants who answered the questionnaire are industry experts from the ‘CircularB’ and ‘ECO4All’ networks. These participants are professors, researchers, and esteemed personnel in the fields of sustainability and circularity practices and are thus very well-equipped to answer the questions. The questions are rigorous, open-ended, and indicative of the skillsets employed by the experts. There is a range of experts from CircularB across Europe who completed the questionnaire, offering a great insight into their transferable engineering capabilities, such as language proficiency and stakeholder collaboration, which vary depending on the country of work. An appropriate sample size was determined through a sample size derivation justified upon the review of many qualitative studies (see Section 3.1.2).

3.1.2. Questionnaire Formulation and Analysis

The purpose of this research is to bridge the knowledge gap identified after reviewing 100+ articles on this topic [8]: What skillsets are needed for the implementation of circular economy in a smart city setting, and what skillsets will produce the best results in practice? On this basis, the semi-structured interviews were preceded by a critical literature review and a desktop study. The following questions aim to attain some background information on the experts, such as their roles and responsibilities, to explore the implementation of CE in smart cities, and to determine the key factors in addressing the knowledge gap, i.e., the engineering skillsets required to perform their jobs. Stakeholder collaboration is a necessity in the development of smart cities; so, information about the involvement of stakeholders will offer insights into the interests of different stakeholders and their input on the project, with the chance of exploring challenges and disputes between engineers and stakeholders and the skills needed to navigate these relationships. The questions concern the areas of skills and experience (E), circular economy (CE), smart cities (SC), mindset indicators (M), and engineering knowledge (K). The questionnaire questions and areas that they target are tabulated in

Table 1. Examples of interview questions designed to gather necessary information and insights from the expert interviews.

Question	Area *
What is your role relating to a smart city or circular project/practice?	E, CE, SC, and K
What are the specific responsibilities of your role?	E
Have there been any challenges which you have faced which have hindered your ability to meet certain goals during the implementation of smart technologies?	E and SC
Have new technologies had an impact on your day-to-day work? If so, what technologies and what impacts?	E and SC
Do you believe that your role could ever fully be rendered obsolete due to the ‘Internet of Things (IoTs)’ or other smart technologies? (Yes/No)	SC
Is there any restriction or enforcement by governmental policy to implement circular practices or economy within the smart city framework?	E, CE, and SC
How do you involve various stakeholders in your smart city project(s)?	E, SC, and M
What do you believe the next steps will be for your business based on emerging circular technologies and practices?	CE and M
Would you like to share any other perspectives on this topic? If deemed relevant to the research these may be used as expert opinions in the dissertation and you will be duly credited.	E
Have you implemented circular economy/practices in your project(s)?	E and CE
In a nutshell, what is the main barrier to the implementation of CE that you have seen in your project(s)?	E, CE, and M
How do you stay updated on the latest developments or updates in the smart technology field relevant to your job?	SC and M
How are privacy and security concerns due to smart city technologies in your work addressed?	SC, M, and K
What role do data analytics and insights from smart technologies play in decision-making processes within your team or organization?	E, SC, M, and K
What educational background is needed for your role?	E and K
What hard skills are needed?	E and K
What soft skills are needed?	E and K
Are there opportunities for professional development?	M
Are there any employee testimonials I can have access to?	E
What skillset is needed to perform your work? Knowledge of any specific disciplines or programs?	E and K
Has the skillset required to perform your job changed since you were first employed?	E and K
Is proficiency in another language preferable for your work?	E and M
How do you apply the notions of life cycle assessments to the decision-making process in a smart city framework?	E, CE, SC, and K

* skills and experience (E), circular economy (CE), smart cities (SC), mindset indicators (M), and engineering knowledge (K).

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A sample size determination was completed before the questionnaires were conducted to ensure that the results would have great statistical power, meaning that the results would indicate that an effect is present (the effect being common transferable skills and capabilities among the industry experts working in the field). This ensures that the results obtained are as repeatable and reliable as possible whilst keeping this study efficient as a sample size that is too large would be inefficient and time-consuming. There are no strict guidelines in research for sample size determination concerning qualitative data. Rather the goal is to achieve a point of data saturation, where the data are repeated to the point where any conclusions are proven without reasonable doubt and further data collection is deemed unnecessary [42]. The most appropriate procedure was to review existing research articles and books concerning the collection and analysis of qualitative data to deduce an appropriate sample size. This is technically a grounded theory study, one that does not have a hypothesis before data are collected; thus, new insights can be derived from data [43,44]. Several research articles online state that grounded theory studies have an average sample size of 20 participants [45], a number that will result in accurate conclusions. One study states that a sufficient sample size for data saturation is 16–24 interviews [46], and two others state that a sample size of 20–30 interviews is recommended [47,48]. A qualitative study [49] on social desirability bias observed a ‘Cronbach’s alpha’ (an indicator of consistency in results) of 0.7 when the number exceeded 12 interviews, which indicated good consistency. A larger number of questions will offer a diverse range of challenges that experts face when implementing CE and will likely indicate a clear effect of the skillsets needed to overcome said challenges.

3.2. Methods

The qualitative data underwent a thematic analysis, which is the process of identifying and analyzing a pattern or effect in qualitative data [50]. Our critical literature review also reveals that the semi-structured interview is the most suitable for our research goal. Finding underlying themes or patterns in the data is crucial to identifying the knowledge gap: what skillset is needed for the implementation of CE in a smart city setting, and what skillset will produce the best results in practice? These can be deduced by the other questions in the questionnaire. Two of the biggest barriers to CE include difficulty setting up an effective circular supply chain and challenges with customer behavior and product redesign [51]. Three questions that are particularly important in resolving these challenges are ‘How are privacy and security concerns due to smart city technologies in your work addressed?’, ‘Is proficiency in another language preferable for your work?’, and ‘How do you involve various stakeholders in your smart city project(s)?’. These three questions are indicators of skillsets that are often overlooked: first, the privacy concerns would indicate hard engineering skills such as network system knowledge, online security, and continuous learning. These skills are vital in the design of a circular economy and its technologies, meaning challenges with redesign will involve problem solving and critical thinking; therefore, understanding what steps industry experts take to combat security concerns will indicate the steps needed to tackle such a big challenge in the CE discipline. Language proficiency is a hard skill that is often overlooked because it is a common language skill in global science [52]; so, proficiency in other languages will likely indicate better soft skills, such as group communication and scientific discussion. Routine transparency and communication with stakeholders (involving customers) will also help to combat one of the biggest issues faced, namely, the challenges related to customer behavior. A company’s proactive efforts to communicate with customers lead to a positive relationship between them [44]. Observing the communication skills displayed by industry experts with their project stakeholders will improve relationships when implementing CE in smart city projects, meaning fewer conflicts and issues will arise. It will also help to inform the stakeholders of the intricacies of the projects being implemented, which will help to maximize the project’s efficiency given that a lack of knowledge is one of the main barriers to CE implementation [40].

4. Results

To identify critical capabilities to enrich the circular economy towards smart cities, we conducted 21 expert interviews with experienced stakeholders across the value chain. Based on the expert interviews, new insights were obtained based on the contour levels (as shown in

Table 2. Contour levels of expert opinions with respect to the significance of engineering skills for implementing circular economy in smart cities. [Note: Green implies low risk and low impact; Yellow implies medium risk and medium impact; Purple implies high risk and medium impact; and Red implies high risk and high impact].

Listed by % of Participants	Criticality
0–25%	Low
25–50%	Medium
50–75%	High
75–100%	Very High

) to demonstrate the criticality of engineering skills required to adopt circularity practices within smart cities.

Expert stakeholders were asked to provide their opinions related to the essential hard engineering skills required for implementing CE in smart cities. Figure 4 portrays the expert opinions about the criticality and influence of relevant hard skills. The majority of stakeholders stress the importance of engineering and sustainability knowledge (71% of stakeholders) but do not understand the importance of research or building information modeling (BIM).

All experts were consulted about the importance and influence of soft skills. However, only 20 experts responded to discussions with respect to stakeholder collaboration. The results of expert interviews related to soft skills for implementing CE in smart cities are portrayed in Figure 5. It is apparent that the expert opinions are consistent and convergent. It is important to note that the majority of experts stress the importance of communication skills.

Based on the expert interviews, the criticality and influence of multi-language proficiency, privacy, and security concerns are illustrated in Figure 6 and Figure 7, respectively. The expert opinions converge on the preference for multilingual proficiency and the considerations of privacy and security concerns within smart city environments.

5. Discussion

5.1. Most Common Hard Skills

A background in engineering and sustainability is the most common hard skill utilized by industry experts, with 71.43% of them outlining the importance of the knowledge concerning their work (see Figure 4), ranking them as highly critical. These data correlate with the research of Sharif University of Technology and the University of Calgary, whose work states that engineering technical knowledge is one of the top factors that positively influence client satisfaction in the delivery of projects [53]. Students with engineering degrees bring a broad range of diverse and highly desirable skills to the market [54], and all these technical and human skills are significantly related to project success [55].

Table 3. Breakdown of interviewees’ expertise.

Discipline	Number of Participant Experts
General engineering	6
A degree (unspecified)	6
Civil engineering	4
Computer sciences and machine learning	4
Environmental science and engineering	4
Construction	2
Architecture	2

presents the most popular results of the participants who answered the question “What educational background is needed for your role?”.

Around 20 participants answered this question; 11 are senior researchers and 3 are professors in universities across Europe. This means that at least 14 participants have completed a master’s degree in a related discipline and are working towards or have obtained a doctorate in a related field. This also means that they will possess the transferable capabilities needed to maximize the success of the projects they deliver. The most popular solution for the most appropriate educational background outlined by the experts was that an unspecified degree was needed, tied with general engineering education, as stated by six experts. These were closely followed by environmental engineering, civil engineering, and comp science and machine learning, each one outlined by four experts. This further reiterates the importance of the skillsets employed by engineers working in the circular economy; with these capabilities and skills having a direct influence on project success, the people involved in the implementation of the circular projects must display such traits to maximize their output in smart city settings where such knowledge skills and talents are sought after [56]. Other disciplines outlined include construction knowledge, architecture, business administration, and various other outlying areas of engineering.

The next most common hard skills employed by the experts were software, computing, and coding, which were rated as highly critical, at 57.14%, followed closely by data analysis and data modeling, also rated as highly critical, at 52.38%. As stated in Section 2.3.2 (Governance of Circular Economy in Smart Cities), digitality is a key aspect of how smart cities operate, which relates to the optimization of technology in a smart city setting. Implementing circular technologies such as the IoT requires architecture, systems, and frameworks implemented and optimized by architects to support data, processing, and endpoint functions [57]. If these skills, which are desired by the experts, were more widely adopted, the current IoT architecture would be redesigned, with the aim of improving and innovating systems, meaning the implementation of CE in smart city settings would have a greater effect.

Security and privacy concerns are another key area of digitality that concerns software, computing, and coding proficiency. When asked “How are Privacy and Security concerns due to smart city technologies addressed in your work?”, 72.22% of the participants said that they take direct action when addressing privacy and security concerns due to smart technologies, of which some actions can be seen in Figure 8. This is indicative of hard skills, such as data analysis and IT, and soft skills, such as risk assessment, communication, and project management [58]. Harnessing these skills will allow CE to be implemented in smart cities in the best way possible as robust security measures will mitigate risks of serious data privacy breaches and disruption of operations, which could occur if the devices harnessing the IoT are compromised, possibly leading to financial losses, user impersonation, and server impersonation [59]. All 27.78% of participants who did not show these concerns currently work in academia. This suggests that these experts do not experience the implementation of circularity practices firsthand but rather have an academic role in the research and development of particular areas of CE.

A total of 23.81% of the industry experts who participated in the questionnaire said that knowledge of BIM is a valuable hard skill for working in the industry. BIM is a modeling software used to demonstrate key characteristics of buildings and can simulate stages of construction over a certain time scale while providing information regarding materials, bills of quantities, energy, emissions, and other LCA information [60]. If these insights were readily available to someone with proficiency in BIM in a smart city setting, the CE could be improved as they offer an opportunity for various sustainability analyses [61], and at the end of the building’s life, BIM can be used to obtain information about the materials and foundations, which can be used to reuse as many materials as possible or to observe if the renovation is possible. Tied with BIM, research skills were also outlined by 23.81% of industry experts. Research skills are required for technical development and gathering data for analysis by computers [62], as well as for understanding and quantifying the data and taking actions to improve the circularity aspects based on the data. This ties in nicely with BIM as workers proficient in both research and BIM can oversee entire circular projects: understanding sustainability data from BIM, utilizing these data, and then making informed decisions on what can be improved using research skills.

5.2. Most Common Soft Skills

Stakeholder collaboration is a key aspect of engineering, which includes liaising with investors, councils, or the community (all of whom may have conflicting interests) to determine a solution that can simultaneously satisfy multiple objectives [63]. Collaborating with stakeholders must be navigated in a way that facilitates trust. As shown in Figure 9, this is one of the key aspects of delivering a project as it has been found that greater trust between the project manager and stakeholders achieves better results [64]. A total of 95% of the industry experts who answered the question “How do you involve various stakeholders in your smart city project(s)?” said that they liaise directly with stakeholders, rating the skill as very highly critical, with five experts conducting workshops for better collaboration, five ensuring full transparency and discussions, and others employing methods such as centralized information and involving them from the design phase to delivery. The positive link between the project manager and stakeholder’s trust and the result of the project emphasizes the importance of the right capabilities of the people implementing circular projects. This is indicative that a lack of collaboration and trust between managers and stakeholders is holding back the progress and effectiveness of smart cities in Europe, and if the skills utilized by the industry experts (95% stakeholder collaboration) were more widespread, there may likely be improvements in the delivery and operations of circular projects in smart city settings.

Communication is highly critical, ranked as the second most popular soft skill among the questionnaire participants, with 71.43% of the experts outlining its importance. There are several aspects of communication that influence the implementation of CE in smart cities. In response to the question “Is proficiency in another language preferable for your work?”, 76.19% of participants answered that it is preferable. English is accepted as the common language for global science [52]; so, scientific discussion is conducted in English. Scientific thinking and discussion is classed as a soft skill, meaning the experts possess social and collaborative processes central to these ideas [65]. The ability to learn a second language is often coupled with higher learning capacity [66], which is a very attractive trait. It indicates that the individual will be better able to solve complex problems that will often be encountered in the digitality aspect of the CE, such as the optimization and installation of the IoT. It is also indicative of continual and multi-disciplinary learning, where the individual has the capacity to acquire knowledge in many disciplines, not just in engineering but perhaps also in business, management, and sustainability subjects, which would help them to take a more well-rounded approach to their work. As well as scientific discussion, communication links back to stakeholder collaboration, as previously stated. Effective relationships built through effective communication are vital for a project’s success [67] and, therefore, the successes of circular projects are easily influenced by communication, ranging widely from project managers and firms working on large-scale frameworks and projects with many stakeholders to workers promoting schemes and educating the public on the circular practices since it has been proven that great communication skills in education have the potential to influence people’s interest and attitude, promoting a better learning atmosphere and other successes [68]. This approach can be used to combat one of the biggest issues in implementing CE, which is a lack of CE awareness (see Section 2.3.1), as having the people with the most appropriate skillset for passing on knowledge will have a profound impact on the public’s awareness of the subject.

Management is the third most important soft skill, according to the industry experts’ answers, also ranked as highly critical, with 52.38% of experts listing it as a skill required to conduct their work. Four areas of management were outlined, namely, time management, waste management, resource management, and project management, which are all related to each other. Project management requires skills such as leadership and interpersonal skills, technical skills, and administrative skills [69]. The technical skills required in project management cover areas of waste and resource management, closely related to the most critical hard skill emphasized by the experts, which is a background in engineering and sustainability. As stated before, technical skills are significantly related to project success, meaning these skills are highly important. Time management is perhaps the most important administrative skill [70]. It is a factor that impacts the quality and success of the project, and therefore, workers in circularity practices working in a timely manner will deliver projects of high quality, which will maximize the potential of sustainability. The third area of project management is leadership and interpersonal skills. Interpersonal skills are desirable in a project manager as they can advocate for a desired state of affairs, which promotes a positive workplace culture and trust between them and clients whilst fully respecting their rights. This will help to solve one of the main issues hindering CE development, which is a lack of long-term strategic goals (see Section 2.3.1), with positive impacts in several areas, such as stakeholder collaboration and communication disciplines, where the worker’s interpersonal skills will help them work towards their goals in circular smart city projects.

Critical thinking and decision-making were highlighted by 38.1% of industry experts as important soft skills required in their roles, ranked as medium on the criticality scale. The circular economy’s performance stems from the quality of the decision-making process [71]. Decision-making is a very important skill to have in conjunction with other soft skills, such as scientific discussion and stakeholder collaboration, as many different stakeholders are involved in circular projects, meaning many decisions are made as a group regarding the development of the projects. In a European context, the different working groups in the CircularB and ECO4All networks work together to create the circularity grading framework, meaning cooperation and group decision-making are necessary to foster innovation.

When asked, “Are there opportunities for personal development in your role?”, 100% of the participants answered yes. Such opportunities are indicative of positive traits and capabilities. Personal development is a major indicator of a growth mindset, a trait of a worker who believes that their knowledge and abilities can flourish and develop, as opposed to a fixed mindset, where a person believes their knowledge and abilities are fixed and cannot improve. People with a growth mindset harness the skill of adaptability, being able to attack new and different challenges amidst the ever-changing climate of CE, a characteristic that is highly sought after in sustainability work as it means that candidates will have greater career interest and better persistence when challenges arise [72].

Coupled with adaptability, it has been proven that a leadership mindset and leadership skills and practices arise from a growth mindset [73]. In this study, 23.81% of the experts outlined leadership and decision-making as important soft skills needed to work in circularity practices. These are obviously very attractive traits for an employee, particularly in project managers, as stated earlier, as their work will inspire other coworkers around them to increase the quality of their work, encouraging a productive culture in the workplace. Parallel to this, a growth mindset is a facet of resilience [74]. Resilience is a key engineering soft skill in the implementation of CE in smart cities as there will be complex systems being installed that harness the IoT, systems that must then be optimized and maintained, which is not always simple. Issues involving IoT include high energy consumption in IoT devices and poor e-waste management [75], both of which reduce the efficiency of the systems. A resilient individual will continue to overcome setbacks until these problems are mitigated, which, again, will inspire positive organizational behaviors in the work environment [76,77,78,79,80] and will improve the efficiency of this circular system in smart city settings.

6. Conclusions

Technologies and innovations alone cannot promote circular economy adoption in the built environment sector. Similarly, an engineer or a scientist alone cannot stop climate change despite their knowledge of the subject. In addition to technical barriers, there are more hidden challenges to overcome in order to encourage the public to adopt a circular economy, which will reduce the demand for raw resources, greenhouse gas emissions, and, eventually, climate urgency. Engineering skillsets and transferable capabilities span a broad spectrum, covering a multitude of disciplines, ranging from technical engineering expertise to project management and people management, all of which have an impact on project delivery and success in some aspect. This research offers a comprehensive view of the indispensable hard and soft skills that industry experts highlight as essential for their work whilst offering insights into how such skills can be harnessed to tackle the main complex challenges faced, which contribute to low circularity ratings, especially in Europe, and to suggest the steps that can be taken to improve said circularity. Overall, this study indicates skill-based solutions to the key factors that prohibit the development of CE. Our findings are robust, supported by a comprehensive sample size determination based on a review of extensive qualitative data analysis literature, ensuring sufficient data to demonstrate clear trends and effects.

The significance of hard skills in navigating the complex issues that prohibit the development of CE in smart cities is paramount. Our results reveal that background knowledge in engineering and sustainability is the most critical hard skill, according to the experts. Other highly critical hard skills outlined by experts include computing, software and coding, and data analysis and modeling. These skills are crucial regarding digitality in governance, allowing engineers to revise current IoT architectures, with the aim of increasing efficiency. Data analysis and modeling skills are also key in understanding, quantifying, and analyzing BIM software data to act on in order to optimize circular systems. The industry experts also highlight that knowledge in BIM is a valuable hard skill for working in the industry, offering an array of information regarding materials, bills of quantities, energy, emissions, and other LCA information. These benefit CE as they offer an opportunity for circularity analysis involving reviewing buildings at the end of their life, with the aim of renovating or reusing as many materials as possible.

Interestingly, most experts stress that stakeholder engagement is a highly critical soft skill. The correlation between the project manager and stakeholder’s trust and the result of the project emphasizes the importance of the right capabilities of the people who implement circularity projects. This is followed by communication skills, which is ranked as highly critical. In addition, the majority of participants state that a second language is preferable. The ability to life-long learn is often coupled with higher learning capacity, suggesting that the individual will be better able to solve complex problems that will often be encountered in the digitality aspect of CE, such as the optimization and installation of the IoT. It has been proven that great communication skills in education have the potential to influence people’s interests and attitudes, which can help to combat one of the biggest issues in implementing CE, namely, educating people on CE practices and behaviors. Management is also ranked as highly critical, as outlined by 52.38% of experts. The related areas of time management, waste management, resource management, and project management all indicate the importance of leadership and interpersonal skills, technical skills, and administrative skills.

With respect to personal development, people with a growth mindset harness the skill of adaptability, being able to attack new and different challenges amidst the ever-changing climate of circularity. Coupled with adaptability, it has been proven that a leadership mindset and leadership skills and practices arise from a growth mindset. A growth mindset indicates resilience, which is a key engineering soft skill in the implementation of CE in smart cities as complex IoT architecture will need to be optimized and maintained, which is not always simple. Issues that reduce the potential of IoT systems include high energy consumption in IoT devices and poor e-waste management; a resilient individual will continue to overcome setbacks until these problems are resolved, which, again, will inspire positive organizational behaviors in the work environment and will improve the efficiency of this circular system in smart city settings.