The recovery point objective (RPO) is the maximum acceptable level of data loss following an unplanned “event”, like a disaster (natural or man-made), act of crime or terrorism, or any other business or technical disruption that could cause such data loss. The RPO represents the point in time, prior to such an event or incident, to which lost data can be recovered (given the most recent backup copy of the data).
The recovery time objective (RTO) RTO defines the maximum amount of time that a system resource can remain unavailable before there is an unacceptable impact on other system resources, supported mission/business processes. RTO must ensure that the MTD is not exceeded.
The Maximum Tolerable Downtime (MTD) is the maximum length of time a BUSINESS FUNCTION can endure without being restored, beyond which the BUSINESS is no longer viable