Virtual commissioning: how we connected 10 automation systems through one digital melt shop

The problem with testing automation systems in isolation

Virtual commissioning of individual machines is well established. You pair a Level 1 or Level 2 system with simulated sensors and actuators, connect it to a PLC, and test it as if the real hardware were there. For a single electric arc furnace or a single ladle furnace, this works.

But a melt shop is not one machine. It is an EAF, an AOD converter, three ladle furnaces, three VD/VOD units, six cranes, transfer cars, slagging stations, heaters, scrap dryers — all producing simultaneously, all depending on each other through shared transport resources and real-time scheduling decisions.

When you test each automation system in isolation, you miss everything that happens between machines: crane transports, ladle routing, tundish logistics, the time dependencies between processes. A ladle furnace automation system has no way of knowing when a ladle will actually arrive — because that depends on what the cranes are doing, which depends on what every other machine needs at that moment.

Higher-level systems — production planning and ladle management — are even harder to test alone. They depend entirely on check-in/check-out signals, machine states, and process events from across the entire plant.

The approach: a digital melt shop as the integration layer

Together with SMS group, we built a solution for a real commissioning project. The idea: use a FESIOS digital melt shop as the shared environment that connects all automation systems into one holistic integration test.

The simulation acts as the missing link. It handles everything that no individual automation system covers:

• Crane transport — six cranes with full route planning, collision avoidance, and inter-crane coordination
• Ladle routing — dynamically calculated based on real-time queries to the production planning system
• Process events — the simulation sends and receives events via OPC UA to synchronize with each automation system
• Time dependencies — every transport runs at real equipment velocities, so timing between processes is realistic

For machines where SMS supplied the automation (EAF, AOD, LF, VD/VOD), the real automation software connects directly to simulated hardware. The simulation receives key events — “tapping complete,” “ready for charging” — and triggers the corresponding transport and logistics actions. Continuous variables like electrode positions or converter tilting angles are updated in real time via OPC UA.

For the production planning system, the simulation queries the schedule after each event to determine where a ladle should go next. For ladle management, it provides check-in and check-out signals as ladles move between positions — exactly as the real identification system would.

What it looks like in practice

The integration test runs in a dedicated testing center. Each machine has its own workstation running the real automation software. In the background, our digital melt shop runs in the browser — visible on a main screen and accessible from every workstation.

The 3D visualization shows the complete plant in real time: cranes moving, ladles being transported, processes starting and finishing. When the EAF automation finishes tapping and sends the release event, the simulation immediately picks up the ladle, queries the production plan, and routes it to the correct next station. The AOD automation can then trigger charging events, and the simulation orchestrates the crane movements accordingly.

Every action follows the real sequence: scrap charging, tapping, ladle transport, secondary metallurgy, casting. The simulation fills in all the gaps that would otherwise require the physical plant.

10 systems, one test run

The project involved 10 automation systems running simultaneously:

• 1 EAF (Level 1/2)
• 1 AOD converter (Level 1/2)
• 3 ladle furnaces (Level 1/2)
• 3 VD/VOD units (Level 1/2)
• Production planning system (Level 3)
• Ladle management system (Level 3)

All connected through the digital melt shop, all exchanging events and data in real time.

What we learned

The shared 3D view changed how the teams worked together. Instead of each workstation operating in its own silo, everyone could see the full production flow — multiple heats at different stations, cranes moving between machines, ladles cycling through the plant. It created a sense of real production that isolated testing never provides.

The time dependencies became tangible. When a checkout signal fired, teams could watch it propagate: the ladle management system updated, the production planning system received the status change, and the simulation reflected the next transport — all in real time.

This approach also extends beyond commissioning. The same setup can train operators on the real automation systems using a virtual environment, without interfering with actual production. New operators get realistic conditions — real software, realistic timing, full plant context — without risk.

This work was presented at ESTAD 2021 in collaboration with SMS group.