# Is Digital Twin Technology Supporting Safety Management? A Bibliometric and Systematic Review
## 1 Introduction  
The fourth industrial revolution--also known as the Industry 4.0 paradigm--is changing current industrial production systems. The Industry 4.0 digital transformation is aimed at the optimization and automation of the previously introduced digitalization by adding the intelligent networking of machines, processes, and people [1]. In recent years, the concepts and theories of Industry 4.0 have become considerably important within the manufacturing sector [2]. One main reason for this increasing diffusion is the use and implementation of hi-tech technologies within the production processes at an affordable cost [3] in order to create smart grids across the entire value chain and networks formed by interconnecting intelligent machines [4]. Within industrial manufacturing contexts, Industry 4.0 entails the networking of data coming from machines, products, and people; in general, this involves the interconnection of smart devices among different plants and factories [5] through tools and embedded components, such as cyber-physical systems (CPSs), Internet of Things (IoT), cloud computing, robotics, systems based on artificial intelligence, and cognitive computation [4].  
Digital Twins (DTs) are key enabling technologies (KETs) that were created to improve the efficiency and profitability of Industry 4.0 systems [6; 7].  
The first applications of DTs in industrial systems focused on developing a \"digitalized copy\" of a production process and/or a product. More recently, through the overlapping with the IoT, DT functionality and interoperability has been \"augmented\" by adding a real-time interaction with the real system [1].  
The availability of virtual and digital information represents an effective solution for improving product design, manufacturing technology, and other critical service processes, such as safety management [8; 9].  
Safety management, as the process of realizing certain safety functions, aims to promote organizational safety and to protect people and property within an organization from unacceptable safety risks [10]. Recently, with the increasing global economic uncertainties, safety management in most organizations is under growing pressure to achieve the best performance, and this requires access to a variety of high-quality safety information [11].  
In the era of Industry 4.0, it cannot be disputed that data and information represent an indispensable resource and a successful key factor for a new paradigm of safety management [12; 13; 14; 15].  
Within the Safety 4.0 framework [16], DT-assisted safety management systems can be implemented to help operators execute complex safety procedures, thus reducing risks and human errors. DT guidance can lead operators through safety tasks and provide them with real-time information regarding the contextual conditions [17]. This can reduce the costs and time required for service and maintenance, decrease oversights and mistakes, and increase safety [18; 19].  
The main purpose of this study is to present the prevailing state of research on Digital Twin technology, its manifold applications, and the intersection between DTs and safety, answering the following research questions:  
RQ1. What are the current publication trends in the domain in terms of the types of studies, time, and affiliated countries?  
RQ2. Which are the influential studies and themes of research in this domain and how have they evolved over the years?  
RQ3. What are the recent research trends, gaps, and areas for future research in this domain?  
The rest of this paper is organized as follows: Section 2 delineates the advent of DTs, their main features, and their background. Section 3 illustrates the adopted methodological framework, while Section 4 covers the findings on the publication trends and on the keyword and cluster content analyses. The study is concluded in Section 5, where future research avenues are suggested.