## 2 Background
### Industrial Maintenance and Maintenance Documentation  
Industrial maintenance aims at keeping machinery running and in good condition. Companies have different maintenance strategies; in the era of data analytics, the trend is towards preventive and condition-based maintenance. Complete optimization of material and workforce costs both per visit and over the equipment lifecycle, increasing equipment uptime, and avoiding risk of breakdown have transformed the nature of maintenance visits. Where earlier it was typical to have predetermined maintenance visits with predefined task lists, modern service companies use real-time sensor data to monitor the condition of the machinery and artificial intelligence to define the optimal time for each maintenance task to be performed. This means that the content of each maintenance visit is different,and the composition of tasks varies across the visits. Thus, maintenance technicians need instructions on what to do as they cannot rely on their experience or tacit knowledge as before. Because of the quest for financial optimization, it is equally important to instruct what _not to do_ on the visit. Regardless of the maintenance strategy and how the composition of tasks for each maintenance visit is determined, it is important that maintenance tasks are performed in an optimal and safe way. Therefore, maintenance methods are carefully designed, authored, tested, documented, and risk assessed. Technical communication is a field that conveys technical or specialized information, uses technology to communicate, or provides instructions on how to do something [32]. The maintenance documentation process is a subcategory of the more generic technical documentation process [33; 34], and the outcome of the maintenance documentation process is a set of maintenance instructions that help the end users, maintenance technicians, complete their tasks in an efficient and safe manner. The content creation process is inherently collaborative, where people from different departments are working together to achieve a common goal. The process starts from maintenance method and outline creation by maintenance method developers. The outline is then passed on to the technical documentation experts, who start working on a draft. The draft instructions are developed iteratively with the maintenance method developers, by reviewing and revising. When both parties are satisfied with the draft, the maintenance method and the safety of the instructions are evaluated with the help of risk assessment experts. If the risk assessment finds deficiencies in the instruction or the method behind the instruction, they are revised and reviewed again until the requirements for safety are satisfied. Finally, the instructions are officially checked and approved by the organization, and then published into relevant delivery channels. See Figure 1 for an overview of the maintenance documentation process. From the technical point of view, the process of documentation review has remained the same for the past years. Even though the use of VR for the technical documentation process has been studied [4], the use of novel technologies, such as VR, has not been implemented for the review and risk assessment of technical instructions in industrial companies. Typically, technical instruction reviews and risk assessments are carried out by sending out links to PDF files or online review portals. If all participants are located on the same site, a face-to-face meeting can be arranged, but global teams rarely have the option of doing this. In practice, meetings are held in conferencing tools, such as Microsoft Teams, or, more often, reviewers comment on the PDF file and send it back to documentation experts via email or file sharing systems. In many cases, the teams have to work without any access to the actual product. As the development cycle in industrial companies is short, the technical instructions have to be completed in an increasingly short time frame, often before any actual prototypes exist [4].