Which metric is best for measuring how quickly services must be restored after an outage?

Which metric is best for measuring how quickly services must be restored after an outage?

• A. MTBF
• B. RTO
• C. MTTR
• D. SLI

Answer: (B)

The key idea here is the downtime threshold you must meet after an outage. Recovery Time Objective captures the maximum amount of downtime that is acceptable before services are considered restored. It directly informs how quickly you must restore operations, guiding your disaster recovery plans, backup frequency, and failover capabilities. If your RTO is very short, you need rapid, automated recovery and highly available systems; a longer RTO allows more tolerance for manual or slower recovery approaches. Mean Time Between Failures looks at how often failures occur, not how quickly you must recover. Mean Time to Repair measures how long it takes to fix something after it fails, which is about actual recovery performance, not the required target. A Service Level Indicator is a broader performance metric for service quality (like latency or error rate) and doesn’t specify the acceptable downtime duration. So the metric that best answers “how quickly services must be restored after an outage” is Recovery Time Objective.

The key idea here is the downtime threshold you must meet after an outage. Recovery Time Objective captures the maximum amount of downtime that is acceptable before services are considered restored. It directly informs how quickly you must restore operations, guiding your disaster recovery plans, backup frequency, and failover capabilities. If your RTO is very short, you need rapid, automated recovery and highly available systems; a longer RTO allows more tolerance for manual or slower recovery approaches.

Mean Time Between Failures looks at how often failures occur, not how quickly you must recover. Mean Time to Repair measures how long it takes to fix something after it fails, which is about actual recovery performance, not the required target. A Service Level Indicator is a broader performance metric for service quality (like latency or error rate) and doesn’t specify the acceptable downtime duration. So the metric that best answers “how quickly services must be restored after an outage” is Recovery Time Objective.