RQ5 aimed to identify the challenges and limitations of the large-scale adoption of DT, IM, and other interconnected immersive technologies in developing an advanced digital ecosystem and integrating them into OHS practices within manufacturing. Technological advancement is widely regarded as a catalyst for sustainable development, driving innovation and improved solutions [
82]. However, advanced digital transformation introduces significant challenges, including high costs and scalability, data privacy and data management complexities, and cultural and organizational resistance. The implementation of IM in manufacturing faces significant challenges, such as cybersecurity, cost, standards compatibility, and computational demands, as metaverse technology continues to evolve and mature [
64]. Technological immaturity is a barrier faced by several industries, such as textiles [
83] and construction [
84]. The challenges and barriers identified through the review of research items addressing RQ5 are discussed in the following section.
4.4.1. Scalability and Cost
The adoption of advanced immersive technologies in traditional workplaces faces significant challenges related to their scalability and cost.
Table 11 outlines the critical obstacles related to scalability and cost in integrating advanced digital and immersive technologies, such as XR, VR, AR, DT, and IM, into OHS practices. These barriers are categorized into two main areas: (1) high costs and investment uncertainty, and (2) technical and infrastructure limitations.
In the high costs and investment category, the main factor is the significant expenses for hardware, software, setup, and skilled personnel. High initial investments and costs related to hardware, software, and professional personnel for maintenance and support create barriers [
68]. This is particularly burdensome for SMEs with limited budgets [
6,
12,
64]. Moreover, integrating these advanced technologies into existing systems often necessitates costly upgrades, further increasing the financial burden. For example, integrating XR into existing real-world production lines may require substantial upgrades to legacy systems [
12], which are old or outdated computer systems or technologies. In addition, the inherent uncertainty surrounding the return on investment (ROI) for these technologies further complicates the decision-making process for many companies, making them hesitant to invest due to perceived risks [
37,
85]. Furthermore, the significant financing and technical support required for building the IM could lead to large enterprises dominating development, potentially fostering industrial monopolies [
4]. This could further prevent SMEs with already constrained budgets and a lack of capital investment from adopting these immersive technologies, along with the uncertainties and risks involved.
In the technical and infrastructure limitations category, several key challenges are highlighted, including the demanding computational and storage requirements of immersive technologies and limitations in the current network infrastructure. Such challenges are highlighted by [
74], where an IoT-based environmental monitoring system in manufacturing encountered packet loss under variable network loads and faced trade-offs between affordability and data stability. For instance, VR, DT, and metaverse applications require substantial processing power and storage, demanding continuous updates and expert involvement, which can be time-consuming and challenging for SMEs [
6,
54,
62,
68]. Furthermore, IM necessitates ultra-high network reliability, extremely low latency, and high throughput, which existing 5G networks may not fully support, thereby impacting critical applications like environmental monitoring, precise control, and immersive experiences [
4]. Hardware design inefficiencies, such as inadequate headset brightness, can also hinder the immersion experience, leading to eye strain, reduced hazard recognition, and training ineffectiveness [
43]. Likewise, the lack of haptic feedback hindering intuitive interaction with virtual objects [
12] also impedes user adoption and overall effectiveness. Ensuring compatibility across diverse technology standards and integrated software tools is another significant hurdle for metaverse systems [
4,
64]. Moreover, human factors play a crucial role, as traditional skills may not directly translate to using innovative technologies, and there is a concern that workers’ natural instinctive responses to abnormalities might be delayed or ignored in virtual environments [
4,
7].
To conclude, lowering the implementation costs of metaverse technology is crucial for its adoption, especially by SMEs. Although immersive environments involve high upfront costs, these are justified by benefits such as reduced safety risks and increased efficiency [
12].
4.4.2. Cybersecurity, Privacy, and Data Management
Digitally driven industrial systems face increasingly complex and evolving security threats as technology advances.
Table 12 outlines the various barriers to the adoption and secure operation of digitally driven industrial systems, categorizing them into (1) cybersecurity and system vulnerabilities, (2) data management and protection, and (3) human and ethical concerns. These advancements have broadened security concerns beyond simple equipment failures to encompass vulnerabilities in crucial operational layers, including process control, monitoring, encryption, and software systems [
3]. The increasing sophistication and interconnectedness of digital systems, such as CPS, DTs, IoT, and XR technologies, pose escalating cybersecurity, privacy, and ethical challenges across industrial environments [
9,
12,
18,
35,
81]. For instance, cyberattacks, such as ransomware, directly jeopardize automated safety systems, leading to unintended operations, compromised protective measures, endangering both workers and operations, and substantial societal and financial losses [
7,
8,
9]. In addition, many IoT devices are produced rapidly without sufficient attention to security vulnerabilities, risks, and potential threats [
3], and their integration into large-scale industrial systems heightens the attack surface, contributing to broader cybersecurity threats and compromising worker health and safety [
53]. Hence, unauthorized access to industrial control systems can cause production halts, data leaks, and safety risks for workers in automated settings.
The second overarching barrier category, data management and protection, addresses the intricate challenges associated with ensuring data integrity, security, and efficient handling in smart manufacturing environments. Cybersecurity in this context is complex due to the lack of standardized protocols, unprotected remote configurations, and integration of diverse socio-technical systems. For instance, DTs are critically reliant on high-quality, real-time data, which is often difficult to collect, manage, and scale securely. The integrity of this data is very important, as inaccuracies can lead to flawed predictions and hazardous situations [
6]. Cyber threats are commonly addressed through cybersecurity measures like data encryption, robust enterprise security architectures, authentication protocols, and blockchain technologies [
15,
18,
53]. Although encrypting industrial data can prevent leakage and tampering, the encryption and decryption processes can delay data transmission, impacting its timeliness and stability, and affecting performance and real-time decision-making [
4]. Furthermore, reliance on cloud computing for centralized data management introduces the risk of data leakage [
4] and limitations in consistency and reliability [
9]. On the other hand, edge computing offers a decentralized alternative to mitigate some of these concerns, but it requires a specific infrastructure, which can be challenging.
Finally, human and ethical concerns explore the profound implications of advanced digital technologies for the workforce. Beyond technical risks, workforce monitoring through advanced digital technologies also raises serious ethical and privacy concerns regarding employee autonomy and data use. The deployment of XR systems, wearable technologies, and intelligent sensors enables the collection of highly sensitive personal data, including biometric signals, emotional states, and motion profiles [
4,
12,
18,
22,
79]. This raises serious ethical questions about employee autonomy, privacy, and consent, with concerns extending to the potential for corporate misuse of such data and vulnerability to external data breaches. For example, data in the IM is exploited by major corporations, with personal information and biometric data already exposed online, raising both privacy and ethical concerns [
4]. Constant monitoring of workers can also induce psychosocial stress, particularly when employees feel pressured to share personal information or adapt to unfamiliar digital environments [
53]. Thus, the confidentiality and appropriate use of the collected health data raise important concerns.
In short, data security poses a significant challenge and is a major obstacle due to perceived vulnerability to hacker attacks and challenges in managing data consistency and integrity. Ensuring respect for fundamental workers’ rights, including privacy, independence, and human dignity, is of significant importance. Therefore, robust security and privacy protocols, encompassing encryption and strict access control, are not only essential for maintaining employee trust and legal compliance but also for fostering a safe and secure production environment that prioritizes worker well-being, aligning with the principles of Industry 5.0.
4.4.3. Organizational and Human-Centric Resistance
The implementation of advanced digital technologies is frequently obstructed by internal organizational resistance and the inherent technical and systemic complexities involved.
Table 13 provides a comprehensive overview of the organizational and human-centric resistance that hinders the adoption and effectiveness of advanced digital technologies in industrial settings. This resistance is not singular but multifaceted, arising from technical complexities, workforce unpreparedness, and health and safety concerns.
Organizational and technical resistance often arises when digital transformation advances faster than the workforce can adapt. New technologies demand new knowledge and skills, which workers may struggle to acquire quickly [
5]. Similarly, a shortage of digitally skilled workers is a major challenge that can increase workload pressure (additional strain) on existing employees [
85], especially older ones [
36], who struggle to acquire the new knowledge and competencies required, leading to increased workload pressure and potential occupational exhaustion. This issue is further compounded by the technical complexity and infrastructure demands of advanced systems like CPS and DTs, which necessitate a deep understanding, complex modeling, and robust infrastructure, presenting considerable challenges for data quality, computational demands, and overall secure and efficient implementation [
6,
9]. Additionally, the limited grasp of these complexities by top management and their narrow focus on basic ICT and automation further impede enterprise-level transformation [
37].
However, the integration of digital technologies introduces new OHS risks by altering traditional work organization and execution, thereby impacting employee health and safety. For example, VR and AR technologies, despite their training benefits, can induce physical discomfort and user experience limitations such as motion and cyber sickness, headaches, and physical strain from wearable devices, making them unsuitable and uncomfortable for prolonged use [
43,
45,
54,
57,
68]. Additionally, it can induce anxiety from heightened virtual interaction, along with physical discomforts like dizziness, tiredness, and potential loss of balance with intensive use [
8,
12,
66], negatively impacting the user experience [
42]. This leads to the ineffectiveness of using VR and AR for safety training, posing a significant obstacle to the use of these technologies [
43,
68]. Moreover, the increased cognitive demands of advanced systems, leading to cognitive overload and mental strain, contribute to heightened stress levels, reduced memory retention, and mental fatigue among workers [
12,
43,
50,
54,
81]. For instance, managing the heavy cognitive load from rapidly increasing data causes high-stress levels among employees [
16], as well as the difficulty of wearing virtual headsets with safety helmets [
66].
Culturally, concerns over automation, such as fear, anxiety, and job insecurity, pose significant barriers, with older workers especially affected due to their higher susceptibility to simulator sickness and stronger resistance to change. Some workers resist cooperation due to stress and fear of job loss [
8]. Older, more experienced workers, who are often less familiar with modern visual technologies, are more prone to experiencing simulator sickness when using VR, acting as a resistance to its adoption [
45]. These anxieties, coupled with a sense of dehumanization and alienation fostered by machine-paced work and continuous monitoring, can erode trust, lower morale, and weaken social support, ultimately impacting worker well-being and dignity. For example, the adoption of advanced technologies has led to growing concerns about dehumanization and unemployment as automation increasingly replaces industrial workers [
7,
16]. User discomfort and resistance to change also reflect broader resistance, where skepticism and negative experiences with immersive technologies, especially among those accustomed to traditional, hands-on approaches, hinder adoption, illustrating the profound human and ethical dimensions that must be addressed for successful digital transformation. For example, traditional professionals still prefer hands-on physical training methods and are cautious about the long-term effectiveness and side effects of VR/AR tools [
45].
To better organize the wide range of barriers identified in the literature,
Figure 14 introduces a tiered framework that categorizes implementation challenges into four levels: (1) Technology and Infrastructure, (2) Operational, (3) Human and Organizational, and (4) Strategic and Economic. Each level represents increasing complexity and broader organizational impact, offering a structured lens through which to understand the multifaceted obstacles to adopting DTs, IM, and enabling technologies to enhance manufacturing OHS. Each level captures a distinct set of challenges that must be addressed for successful adoption.
At the base, Technology & Infrastructure challenges are especially prevalent among SMEs, which often lack the digital maturity required for DT and IM integration. Inadequate IoT networks, limited real-time data capabilities, and outdated legacy systems contribute to fragmented data environments and hinder synchronization efforts, as highlighted in the literature. These foundational gaps create significant barriers to the deployment of responsive, real-time safety systems.
Moving up the framework, operational challenges involve the practical complexities of integrating advanced technologies into existing workflows. Cybersecurity risks, system instability, and high resource demands for XR and CPS are common concerns. Many older industrial setups also struggle with the scalability and latency requirements needed for predictive analytics, making seamless integration difficult without substantial upgrades.
At higher levels, Human & Organizational and Strategic & Economic barriers become more pronounced. Resistance to change, digital skill gaps, and cognitive overload from immersive systems are frequently cited persistent issues. Strategically, many organizations lack a clear roadmap for immersive safety technologies and are hesitant to invest due to high upfront costs and uncertain returns on investments. As a result, many initiatives remain in the pilot phase. Addressing these layered challenges requires a coordinated approach that combines affordable pilot projects, targeted workforce training, and strong leadership commitment to drive digital transformation in safety practices.
To overcome these adoption challenges and barriers, especially for SMEs with limited resources, budgets, and investment challenges, several affordable strategies can be used. For instance, cloud-based DTs eliminate the need for expensive on-site systems by offering scalable simulations through flexible, subscription-based access. Similarly, simple lightweight XR tools, such as AR on smartphones or tablets, provide immersive experiences without costly headsets. These are particularly effective for AR-based training and work instruction overlays. Furthermore, open-source platforms such as Unity and Unreal Engine allow flexible, low-cost development, making it easier and cheaper to build customized virtual training environments or monitoring tools without the need to pay licensing fees. This is also supported by [
74], whose use of wearable and wireless sensor nodes illustrates practical deployment scenarios of IoT for environmental monitoring that align with the goals of OHS. Low-cost solutions are attractive but can suffer from latency, limited processing power, and unstable communication. Finally, starting with small pilot projects for single use cases like ergonomic risk assessment or VR safety training, that is, phased adoption strategies, also helps teams learn and build skills and confidence before scaling up. These approaches reduce financial and technical barriers, enabling organizations to explore the benefits of immersive technologies without facing overwhelming initial costs, while supporting the human-centered and adaptable goals of Industry 5.0.
In summary, successfully navigating digital transformation in industrial systems requires a holistic approach that moves beyond purely technical solutions. Addressing the complex interplay of scalability and cost factors, cybersecurity threats, data management complexities, and profound organizational, cultural, and human-centric resistance is crucial for fostering a truly secure, efficient, and human-centered industrial future. Addressing these challenges requires not only technical solutions but also organizational change strategies and policy-level support for digital safety innovation.
To conclude, the five RQs posed in this study are addressed across multiple technological domains, each linked to specific enabling technologies and supported by the synthesis in
Section 4.1. RQ1 was examined through the application of DTs, IoT, and sensors, which enable real-time modeling of work environments and ergonomic risk assessment. RQ2 is addressed by exploring how the IM, along with immersive technologies such as VR and AR, supports immersive safety training and virtual collaboration. RQ3 focuses on the integration of DT, IM, IoT, AI, CPS, and COBOTS into a unified advanced digital ecosystem that enhances OHS outcomes using predictive intelligence. RQ4 highlights the benefits of immersive technologies in improving worker engagement and enabling real-time adaptation to dynamic environments. Lastly, RQ5 addresses the challenges associated with implementing these advanced systems, particularly those related to technological complexity, worker trust, and financial constraints. Together, these responses provide a comprehensive understanding of how emerging technologies can be strategically aligned to support intelligent, human-centric safety management in smart manufacturing and advance towards Industry 5.0.