## 3 Results and Discussion
### Scientific Mapping
#### 3.2.1 Application Fields and Methods  
The application field of an article was defined similarly to [56]'s approach as the industry and/or technical environment targeted by the study. One of the twenty articles selected is a literature review [49] that assessed some of the studies under investigation. As a result, we omitted it from our quantitative analysis of application fields in order to avoid counting the same study twice. The application fields observed can be divided into three main categories: (1) automotive industry, (2) industrial machinery manufacturing, and (3) laboratory environment or field undetermined. Figure 4 shows the distribution of papers in each category. The automotive industry was the subject of seven articles (37%) [43; 46; 48; 50; 52; 54; 55]. It was expected that a substantial number of virtual reality studies would be conducted in the vehicle industry. These findings are congruent with those of [56]. The importance of \begin{table}
\begin{tabular}{c c c} \hline \hline
**Ref.** & **Title** & **Publication Year** \\ \hline
[52] &
\begin{tabular}{c} Virtually the Same Experience? Learning from User Experience \\ Evaluation of in-Vehicle Systems in VR and in the Field \\ \end{tabular} & 2019 \\ \hline
[53] &
\begin{tabular}{c} Virtual-Reality-based Approach for Cognitive Design-Review and \\ FMEA in the Industrial and Manufacturing Engineering \\ \end{tabular} & 2019 \\ \hline
[54] &
\begin{tabular}{c} A Transdisciplinary digital approach for tractor’s \\ human-centred design \\ \end{tabular} & 2020 \\ \hline
[19] &
\begin{tabular}{c} Optimizing the Design Review Process for Cyber-Physical Systems \\ using Virtual Reality \\ \end{tabular} & 2020 \\ \hline
[20] &
\begin{tabular}{c} Supporting teamwork in industrial virtual reality applications \\ \end{tabular} & 2020 \\ \hline
[55] &
\begin{tabular}{c} Implications of Virtual Reality on Environmental Sustainability in \\ Manufacturing Industry: A Case Study \\ \end{tabular} & 2021 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
Figure 4: Application fields. the automobile industry may be related to the fact that virtual technologies have long been utilized in this sector in a range of specialties and applications, such as manufacturing, training, and maintenance, to mention a few [13; 57; 58]. Departments such as design, engineering, maintenance, and assembly are already using the technology to support practically everything in the automotive sector, from product development to task assistance in machine assembly or maintenance procedures. Furthermore, the automotive industry is one of the most mature manufacturing industries, with cutting-edge technologies being used for the first time on a regular basis [56]. Regarding the evaluated systems, three studies examined the virtual interaction with an automobile multimedia system, utilizing distinct basic functionalities and, as a result, producing diverse usability testing scenarios. Among the functions are a navigation system, air conditioning, a phone, a radio, a driving assistance, and car parking. Other systems undergoing design review or usability testing include a BMW vehicle's exterior design and Audi [46] and Volvo multimedia stations. Some usability tests guided interaction operations in which participants were immersed in dynamic virtual environments, such as driving a vehicle in a virtual city [46]. For dynamic testing [46; 52], participants drove on public roads in a real-world setting, interacting with the vehicle's panel controls and performing tasks as assigned by the moderator. Each participant interacted with the digital system while driving around virtual streets in the virtual usability testing environment, while a moderator observed the participant's behavior and collected metrics. Two studies did not consider how individuals interacted with a product prototype. The authors of [43] focused on design issues, asking their participants to utilize a variety of assessment techniques to determine the best way to interact with a virtual automobile model.