The FlowFuse server lives up in the IT infrastructure; the Remote Instances live down in the OT environment on the equipment. The server deploys to and manages them across the IT/OT boundary, while each Remote Instance keeps running locally if the link drops.
Use it when — IT owns and hosts the platform, but execution must sit next to the machines in OT.
The FlowFuse server sits inside the plant, firewall-segregated in a DMZ. It reaches corporate systems through a controlled uplink to a Remote Instance up in the IT network, and manages Remote Instances on IPCs and embedded hardware in the OT network below. Nothing reaches OT except through the firewalls.
Use it when — Security policy keeps the platform inside the plant boundary, exposed only through a DMZ.
The DMZ pattern taken to its extreme: a self-managed FlowFuse runs on a server inside an isolated OT network with no internet at all. It manages that site's instances and devices entirely within the OT boundary — nothing goes in or out.
Use it when — Site security policy forbids any internet traffic in or out of the OT network.
Instead of a Remote Instance on every device, deploy one FlowFuse server close to the line and run several Hosted Instances on it — each doing the work an edge device would have done, talking to its equipment directly. Fewer physical boxes to buy and maintain, same separation of concerns.
Use it when — You want the edge workloads consolidated onto nearby server hardware to cut device count.