## 6 Discussion  
Practical experience with virtual commissioning applications has demonstrated that modern simulation methods and digital enterprise tools can be effectively utilized in the design and validation of automated assembly systems, particularly in the testing phase. This approach enables early verification of the virtual model's accuracy, focusing on layout optimization, collision detection, and PLC control program testing, even before the physical system is manufactured. However, it has also become evident that virtual commissioning must be strategically integrated into the entire planning and engineering workflow rather than being treated as an isolated process step. To maximize its benefits, it is essential to analyze the existing development process, clearly define objectives, and select the most suitable digital enterprise tool based on the specific requirements of the application domain. Further advancements in digital enterprise environments and automation technology are expected to facilitate the adoption of virtual commissioning. Key developments include the expansion of open data exchange formats, such as AutomationML, and the integration of standardized interfaces in simulation and automation software. While Matlab Simulink is widely used for control system simulation, digital twin models are integrated into real automation workflows for virtual commissioning and system validation in industrial applications. Unlike Matlab-based simulations, which are operated offline, the digital twin methodology is synchronized in real time with PLCs, SCADA, and MES systems, ensuring direct interaction with industrial processes. Instead of relying on external computational engines like Matlab, an internal scripting solution is implemented for LB modelling, allowing seamless integration within the simulation framework while maintaining real-time execution compatibility. Additionally, progress in software-based control systems for robots and PLCs will enhance the capabilities of virtual commissioning. Improvements such as direct access to hardware control functions, increased instance capacity (e.g., multiple controllers operating on a standard PC), and simulation of safety functions could significantly enhance the efficiency and profitability of virtual commissioning applications. Despite its advantages, virtual commissioning has several limitations that must be addressed. One major challenge is the time-intensive manual modelling of kinematics, which highlights the need for automated methods to generate kinematic models more efficiently. Additionally, during the design of logical behaviour models, it is crucial to consider various operational scenarios to enhance simulation accuracy. Another limitation is the inaccuracy of timing estimates within the logical behaviour model. Since movement durations are typically based on approximations, achieving a 1:1 match between the simulation model and the real system remains difficult. This means that some objectives of virtual commissioning cannot be fully realized, and the simulation reaches its limits in real-time capabilities, though this is not the primary focus of Tecnomatix Process Simulate. Furthermore, Tecnomatix Process Simulate is a complex software tool requiring significant investment not only in licencing costs but also in training and long-term employee education. As it operates on database-driven architecture, users must have basic knowledge of database installation and management. Finally, the complexity of interfacing between the simulation environment, OPC DA server, and PLC should not be underestimated, as demonstrated in this project. The proper configuration and integration of these components are essential to ensure seamless communication and accurate simulation results. In this context, it is important to acknowledge that the PLC model S7-300 (CPU 313C-2 DP) and WinCC/TIA Portal V14 used in this study represent older hardware and software versions, which are considered legacy systems in modern automation.