implementing-patch-management-for-ot-systems

# Implementing Patch Management for OT Systems ## When to Use - When establishing a formal OT patch management program for the first time - When responding to critical ICS-CERT advisories affecting deployed OT systems - When preparing for NERC CIP-007-6 or IEC 62443 patch management compliance audits - When planning patch deployment during limited maintenance windows in continuous operations - When evaluating compensating controls for systems that cannot be patched **Do not use** for IT-only patch management without OT considerations, for emergency patching during active cyber incidents (see performing-ot-incident-response), or for firmware upgrades that change PLC functionality (requires separate change management). ## Prerequisites - OT asset inventory with firmware/OS versions for all patchable systems - Vendor patch notification subscriptions (Siemens ProductCERT, Rockwell, Schneider, etc.) - Test/staging environment mirroring production OT systems for patch validation - Maintenance window schedule aligned with process shutdowns and turnarounds - Change management board approval process including operations and safety representatives ## Workflow ### Step 1: Establish OT Patch Management Program Define the patch management lifecycle adapted for OT environments where availability and safety take priority over immediate vulnerability remediation. ```python #!/usr/bin/env python3 """OT Patch Management Program Manager. Tracks patches for OT systems, manages risk-bas...