## 4 Results
### RQ1: What Was the Significance of People Factors in the Digital Twin Projects?
Because of the nature of the project, no core information systems were used as a consistent data feed, but the project had to follow corporate policy for granting access, and security rules for encryption and other data aspects. In Project 1, a data analytics tool (Power BI), workflow visualization software (Knime), a process management application (AAP), and an SQL database running on-premises were used to bring together data from various existing sources (Figure 4) to facilitate simulations of past production runs. These simulations--the digital twin--take past data relating to component manufacturing, product assembly, and product usage from the SAP ERP system. The DT combines this with test bench data to develop simulations of the manufacturing processes and allows end-user access to develop and configure different simulation scenarios. The system is located largely on-premises with some use of cloud technologies, but the entire system may be moved to the cloud in the near future. The data from the SAP system are retrieved every 15 min. As regards integration, [PERSON] highlighted the use of APIs but also \"quite a lot own development\" to create \"hybrid API access\". In Project 2, the DT is based around the Delmia digital manufacturing software package, a capacity planning tool, which monitors and controls the \"Advanced Manufacturing Execution Assets\" of the company. It is linked with the Siemens PTC which is an open-source platform for monitoring and storing data from IoT and other devices. This allows \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Technology/Project** & **Project 0** & **Project 1** & **Project 2** \\ \hline Extended Reality & NO & NO & NO \\ \hline Workflow/3-D Modelling & YES (PDTec) & YES (Knime/AAP) & YES \\ \hline Data Analytics/Big Data & YES & YES (Power BI) & YES (Power BI) \\ \hline Edge Processing & NO & YES & NO \\ \hline Internet of Things & YES & YES & YES \\ \hline Data Thread/APIs/Webhooks & YES & YES & YES \\ \hline \multirow{3}{*}{Corporate Information Systems} & \multirow{3}{*}{NO} & YES (SAP/ & YES (Delmia/Siemens \\  & & Axialant PLM) & PTC/Axalant PLM) \\ \cline{1-1} \cline{2-4} \end{tabular}
\end{table} 
Table 2: Technologies used in the 3 DT projects. the simulation of production processes prior to the launch of a product. Integration has been problematic, [PERSON] noting that \"there is not much integration with other systems yet\", and there is \"no data or interface to other systems but [we are] using data from the PLM system\" and \"the interface with PLM is manual, there is no interface available to see the release of product variation\". There are 9 databases feeding the system--but the \"number of databases will be reduced\". The data from the digital twin \"is stored in regional databases and it is accessed via Power BI\". [PERSON] indicated, however, that technology integration issues, although evident, were not a significant problem. This contrasted with the other two interviewees, who viewed technology integration as a significant issue as yet unresolved (Table 3, Statement 7). Nevertheless, [PERSON] noted that the \"next step will be integration with the PLM system\".