SI-13(3)—Manual Transfer Between Components
>Control Description
Manually initiate transfers between active and standby system components when the use of the active component reaches [Assignment: organization-defined percentage] of the mean time to failure.
>Supplemental Guidance
For example, if the MTTF for a system component is 100 days and the MTTF percentage defined by the organization is 90 percent, the manual transfer would occur after 90 days.