Today, OT is being operated less and less frequently in a completely independent environment. If there are dependencies with other systems, networks, or services, failures or security incidents in the IT network in question might also affect OT.

The availability of the OT and its processes can be severely affected, especially if these systems and networks are not under the direct control of the operator. Furthermore, incidents or errors usually require external support.

Examples of dependencies with other systems and networks include Internet connections, shared infrastructure components, operational management and monitoring by service providers, or the increasing use of cloud services.