Corporate IT rolls VLAN changes, certificate updates, and firewall rules on schedules that ignore batch cycles. OT teams discover outages when historians flatline mid-run. Coordination is not bureaucracy—it is how you keep both groups employed after go-live.
Practical governance
- Single change calendar with OT veto on production weeks flagged by operations.
- Rollback plan tested on a non-production VLAN mirror where possible.
- Named OT contact on every IT ticket touching plant subnets.
- Post-change verification script: ping, tag read, and alarm flood check.
Documentation both sides can read
OT network diagrams with IP lists dated and owned. IT CMDB entries that name SCADA servers and PLC subnets, not only “manufacturing.” We facilitate working sessions so neither side speaks only in acronyms the other ignores.
Summary
Segmentation projects fail at handover. Treat IT–OT coordination as ongoing operations, not a one-off project closeout slide.