# When Operation Technology Meets Information Technology: Challenges and Opportunities
## 5 Discussion and Limitations of the Study  
We argue that this work differs from the current state-of-the-art because it discusses how to use the AAS to integrate OT and IT in an industrial environment, with a simple but effective use case, rather than just using it to implement a specific OT application. In particular, Ref. [19] describes data conversion between the AAS of a motor and Excel, which is generally used to manage the business-related data of enterprise applications, in order to ensure robust data exchange between enterprise and control applications. Our solution not only enables interoperable data exchange between OT and IT applications but also permits controlling OT devices via IT protocols. Moreover, Ref. [20] explains how it is possible to apply AAS in the context of service robots: this use case represents a clear example of IT/OT integration; however, no practical implementation is presented nor clear results reported. Likewise, a reference AAS architecture for safety and security is presented in [21], but only through a conceptual view. Therefore, to the best of our knowledge, the only academic research that presents clear results is [17]. In the mentioned work, AAS is employed for runtime monitoring of data, reflecting the resource usage and performance of devices and services in Industry 4.0 installations, and results are evaluated in terms of response time. Considering that OT device control is one of the pillars of I4.0, the aforementioned solutions clearly lack this aspect, which is instead addressed in our solution.  
Finally, as highlighted in [45], even though several publications mentioning the synchronization of cameras using PTP are available, in reality, they can be grouped into two main methods:  
1. Synchronization of computers connected to a network using PTP, while the cameras are still synchronized using NTP with the computers. Hence, the synchronization procedure involves the synchronization of multiple computers connected in a network rather than the cameras.
2. Synchronization through a master-slave architecture, where each camera connects to the computer through a frame grabber card. The clocks of the master computers in the architecture are synchronized using PTP.  
In our case study, we exploit the master-slave architecture; however, as an aspect of novelty, we employ cameras provided by our industrial partner, which natively support PTP without the need for an external computer.  
The system proposed also has some critical points: one is bonded with the development of the AAS, which requires writing the configuration model of the asset to interact with; so, it cannot be automated. Another possible critical point derives from the difficulty to create the configuration of OPC UA; this task is not automatized yet and relies on the system administrator.  
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**\# of Devices** & \multicolumn{2}{l}{**Human**} & \multicolumn{2}{l}{**AAS**} \\  & **Average** & **Standard Deviation** & **Average** & **Standard Deviation** \\ \hline
1 & 97.85 & 4.04 & 0.45 & 0.27 \\
2 & 136.75 & 3.91 & 0.66 & 0.34 \\
3 & 190.98 & 6.42 & 5.89 & 0.27 \\
4 & 266.11 & 7.43 & 5.58 & 0.31 \\
5 & 371.20 & 3.16 & 5.65 & 0.25 \\
6 & 518.12 & 5.28 & 5.87 & 0.31 \\
7 & 722.38 & 5.45 & 5.49 & 0.31 \\
8 & 1008.16 & 5.13 & 5.42 & 0.29 \\
9 & 1406.41 & 6.74 & 5.09 & 0.28 \\
10 & 1962.60 & 8.48 & 5.26 & 0.29 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Mean and standard deviation of the time to perform PTP reconfiguration physically (by human intervention) and automatically (using AAS) in our target company. Five samples were collected for every case.