The weaknesses of this setup include the following:

• The OPC UA server will gather data from different data sources. For this reason, it becomes a crucial device from the perspective of the I-IoT data flow. If it experiences downtime, this implies the entire I-IoT data flow breaks and we lose data from all data sources to which the OPC UA server is connected.
• In case of partial data loss, it is not easy to understand and identify which underlying data sources are involved. It is also difficult to identify the issue causing the interruption.