As part of determining how critical an asset is, you need to understand the following terms:
Maximum tolerable downtime (MTD): The maximum amount of time that an organization can tolerate a single resource or function being down. This is also referred to as maximum period time of disruption (MPTD).
Mean time to repair (MTTR): The average time required to repair a single failed component or device when a disaster or disruption occurs.
Mean time between failure (MTBF): The estimated amount of time a device will operate before a failure occurs. This amount is calculated by the device vendor. System reliability is increased by a higher MTBF and lower MTTR.
Recovery time objective (RTO): The time period ...