Tier III
An Uptime classification meaning concurrently maintainable: any component can be serviced without taking IT load down.
Current numbers
Tier III / IVUptime Tier III/IV outcomes: concurrent maintainability vs fault tolerance under the standard's defined conditions
Tier III / IV outcomesUptime Tier III concurrent-maintainability and Tier IV fault-tolerance outcomes under the standard's defined conditions
~25–40% facilitycapital premium for Tier IV (fault-tolerant) over Tier III (concurrently maintainable)