How do you implement virtualization for industrial control systems?

ICS virtualization design: hypervisor selection (VMware, Hyper-V - validated for industrial applications), server sizing (CPU, memory, storage for all VMs plus headroom), network design (virtual switches, VLANs, physical network separation), storage architecture (local vs SAN, RAID for reliability), and licensing considerations. Migration strategy: assessment of current systems, compatibility testing, phased migration with rollback capability. Benefits: hardware consolidation, easier disaster recovery, simplified deployment. Considerations: don't virtualize safety systems, maintain physical segregation where required, ensure time synchronization, and document VM-to-host mapping. Test failover scenarios thoroughly.