RTO (Recovery time objective) is the time during which a system can remain unavailable due to an accident or failure. The system can be either hardware infrastructure, software or web service.
Depending on the business requirements for RTO, the time can range from a few seconds to several days. The lower the RTO value, the more expensive the maintenance, so when calculating the recovery time, not only the possible damage from system downtime but also the maintenance costs are taken into account.
RTO conditions usually come from company executives. The service personnel must provide the approved figures, taking into account the budget. If the maximum allowed downtime is 2 hours, it means that the system must be back up and running within 120 minutes at the latest.
The RTO may vary for different elements of the system. For example, the recovery time for critical services may be minutes or seconds, while for those that do not directly affect business processes it may be hours or a day.