OT change management that auditors actually trust
Approve, deploy and audit every change to PLC code, SCADA tags, HMI screens, recipes and safety configuration — in one place. Built for IEC 62443, NERC CIP, GxP and IATF compliance, without forcing your controls engineers into a ticketing tool.
What counts as an OT change
PLC code
Logic edits, routine changes, function-block swaps, firmware updates.
SCADA tags
Point database additions, alarm threshold edits, scaling changes.
HMI graphics
Screen layout, button bindings, operator permission scopes.
Recipes
Production recipes, setpoints, batch parameters and ingredient lists.
Machine parameters
Drive parameters, IO config, safety thresholds, network topology.
Request → Review → Deploy → Audit
Request
Engineer files a change with the proposed diff attached.
Review
CAB or single approver reviews the diff, risk and deployment plan.
Deploy
VEM pushes the approved version, captures before/after signatures.
Audit
Immutable record links request, approval, diff and deployment.
ITSM tool vs OT-native change management
| Capability | Generic ITSM (ServiceNow, Jira) | VEM OT change management |
|---|---|---|
| Approval workflow | Configurable, IT-shaped | Configurable, with OT segregation-of-duties |
| Change capture | Free-text in the ticket | Actual diff of PLC, SCADA, HMI, recipes |
| Deployment record | Comments on the ticket after the fact | Before/after signed snapshots tied to the change |
| Audit trail | Ticket comments | Immutable, signed log tied to the controller |
| Evidence pack | Manually assembled from screenshots | Generated PDF per change |
Coverage by regime
A real shift in posture
A mid-sized specialty chemicals plant ran change control on a spreadsheet and a shared mailbox. Every IEC 62443 audit cycle consumed three weeks of engineering time reconciling tickets against actual controller state — and one in five sampled changes had no documented approver. With VEM, the same audit cycle now runs in two days: every change in scope is captured automatically, with the diff, the approver and the post-deploy signature attached. The auditor pulls a sampled change and sees a complete evidence pack, generated, not assembled. Plant engineering got three weeks per year back; the QA team stopped writing CAPAs for documentation gaps.
OT change management is the approval and audit layer. PLC backup software is the capture and restore layer underneath. They share the same signed version history.
Common questions
Bring every OT change under one approval and audit trail.
A short working session with our team — we'll walk through your current change-control posture and show VEM running against a controller from your stack.
Book a demo →