Which of the following is the MOST important key performance indicator (KPI) to monitor the effectiveness of disaster recovery processes?

Percentage of IT systems recovered within the Mean Time To Restore (MTTR) measures operational efficiency but does not directly validate the recovery against business-defined RTOs.

Percentage of issues resolved on time during a test focuses on process management within the test, not the effectiveness of the disaster recovery plan in meeting actual recovery objectives.

Percentage of IT systems included in the disaster recovery test scope indicates planning coverage, not the actual performance or success of the recovery operations.

Recovery Time Objective (RTO) represents the maximum acceptable duration of downtime following a disruption, which is a business-critical metric. Monitoring the percentage of systems that successfully meet their RTO during a disaster recovery indicates whether the disaster recovery plan effectively restores business services within the required timeframe, directly measuring its overall success and alignment with business needs.