Recovery Time Objective (RTO) is a predetermined amount of time a business solution or process can remain offline following a disaster or incident. It will be different for each business and process but it essentially says "this is how long our business can survive without process or system XYZ." For example a warehousing system for a retail store may have an RTO of 24 hours, because stores can continue selling existing inventory but will likely run out in about a day without new shipments from the warehouse.

Real Time Actual (RTA) is sometimes used for tracking actual recovery times during rehearsals or incidents. MTTR and MTTD are Mean Time to Detect/Recover and are specifically used for cyber security incidents. They are metrics for tracking the time it takes to detect a threat, and recover or remove the threat.