Implementing IEC 62443 Security Zones When to Use - When designing a greenfield OT network architecture for a new industrial facility - When retrofitting security zones into an existing flat OT network after an assessment finding - When implementing network segmentation to comply with IEC 62443-3-2 certification requirements - When upgrading from basic VLAN segmentation to policy-enforced zone/conduit architecture - When an IT/OT convergence project requires defining security boundaries between enterprise and operational networks Do not use for IT-only network segmentation (see implementing-n…