Asset Inventories That Stay Up-to-Date in OT

You can’t secure what you don’t know exists. In operational technology (OT), asset inventories are the foundation of vulnerability and patch management — yet they often fall out of date within weeks. Keeping them live requires automation, not spreadsheets.

Why Static Inventories Fail

• Manual updates can’t keep pace with hardware swaps and firmware changes.
• Offline or isolated systems are often missed entirely.
• Lack of integration between CMDB, SCADA, and network monitoring tools.

Modern Approaches

• Passive discovery: Capture broadcast and ARP traffic to identify connected devices safely.
• Tag correlation: Match IP, MAC, and firmware data with historian or PLC tag lists.
• APIs and connectors: Sync with IT CMDBs like ServiceNow for unified visibility.

Key Metrics

• Coverage rate (% of known vs detected assets).
• Average update interval (days since last seen).
• Firmware version compliance across sites.

Example Use Case

A global F&B manufacturer automated asset discovery via passive OT sensors integrated with their CMDB. Inventory accuracy reached 98%, supporting faster patch prioritization and SBOM correlation.

Related Articles

• Vuln Scanning without Breaking the Plant: Safe Methods
• SBOMs for PLCs and HMIs: What’s Realistically Possible
• Coordinated Disclosure with Vendors: How to Do It Right

Conclusion

Accurate asset visibility is step one in every OT security journey. With automated discovery and correlation, your inventory becomes a living system — not an annual audit.