# Development and Future Trends of Digital Product-Service Systems: A Bibliometric Analysis Approach
## 1 Introduction  
Manufacturing companies' business strategies are evolving thanks to Industry 4.0 [1]. Additionally, Industry 4.0 integrates digital technologies, like IoT [2], Big Data [3], and AI, into the process of producing goods [4]. Its objective is to create smart, networked machines that enable real-time monitoring, adaptive manufacturing, and data-driven decision-making in order to increase efficiency and production [5, 6]. Industry 4.0 stimulus manufacturing firms involved in research and development activities in the field of Product-Service Systems (PSS) [7]. Furthermore, smart factories and PSS are inextricably linked, since both ideas use digital technology to change traditional manufacturing processes into more efficient, flexible, and customer-centric operations [8, 9]. They exchange data, procedures, and goals in order to produce products and services in a smooth and customer-centric manner [10]. They help businesses to react to changing market needs, create tailored experiences, and constantly enhance their offers by working together [11]. Figure 1 shows the concept of the smart factory. This smart factory idea allows PSS to have a greater effect on the environment, allowing sustainable growth [13]. Moreover, research and development activities in fields of PSS provide insights into the new focuses of manufacturing, such as digitalization, sustainability, resilience, service orientation, and similar new contexts [14; 15]. Manufacturing companies also attempt to add more digital components to the services they provide alongside their goods [16]. The transition from conventional PSS to digital PSS is, thus, supported by Industry 4.0 ideas [17; 18]. Many studies began by looking into established ideas, like servitization and product-related services, but they now concentrate more on digital servitization or digital services that are provided alongside goods [19]. To ensure client happiness, digital PSS offers a combination of goods, services, and cutting-edge technologies [20]. Additionally, Digital PSS allows industrial companies to outperform their competitors in the market [21]. The previous studies attempted to examine the significant impacts of the benefits of PSS, such as client loyalty, profit, income, and market diversity, in accordance with the various benefits offered by Digital PSS [22]. Furthermore, Digital PSS are in favor of the new production approach known as Industry 5.0 [23]. The transformation in the connection between people and the automated systems that are already widespread in production contexts is the starting point for Industry 5.0 [24]. Figure 2 shows the practical applications of robots in Industry 5.0. Figure 1: Smart Factory Concept [12]. Figure 2: Usage of robotics in manufacturing processes [25]. Cobots, which can operate alongside human operators, are developing as critical components of Industry 5.0 [26]. These robots are intended to supplement human abilities by undertaking repetitive, risky, or physically demanding activities [11]. Cobots thrive in activities requiring frequent changeovers and flexibility, allowing quick adjustments in production to suit changing market needs [27]. Furthermore, cobots outfitted with sophisticated sensors and vision systems assure constant product quality by identifying faults and abnormalities in real time. Manufacturing companies can become more resilient, viable, and able to build relationships with their stakeholders thanks to digital PSS [28]. Different groups of stakeholders, including manufacturers, vendors, sellers, maintenance staff, and consumers, are included in digital PSS and linked to one another via various digital technologies [29; 30]. Some studies, on the other hand, indicate that in some instances, the implementation of digital PSS in manufacturing companies results in poor performance [31]. One of the primary reasons is that manufacturing firms do not know what types of digital services they should include in their product offerings based on their innovative or technological level [32].