N10-009 Question 217
Single answerDR metrics: Recovery point objective (RPO), Recovery time objective (RTO), Mean time to repair (MTTR), Mean time between failures (MTBF)A healthcare clinic is reviewing its disaster recovery plan for a patient scheduling application. Management states that after an outage, the application must be restored within 2 hours, and the business can tolerate losing no more than 15 minutes of appointment data entered before the failure. Which option correctly identifies these two requirements?
- A
RTO is 2 hours, and RPO is 15 minutes
- B
RPO is 2 hours, and MTTR is 15 minutes
- C
MTBF is 2 hours, and RTO is 15 minutes
- D
MTTR is 2 hours, and MTBF is 15 minutes
Show answer and explanation
Correct answer: A
Explanation
In disaster recovery and business continuity planning, RTO and RPO are business-defined targets, while MTTR and MTBF are operational reliability metrics. RTO answers, "How quickly must the service be restored?" RPO answers, "How much data loss is acceptable?" In this scenario, restoring the scheduling application within 2 hours maps to an RTO of 2 hours, and losing no more than 15 minutes of entered data maps to an RPO of 15 minutes. By contrast, MTTR is an average measurement of how long repairs typically take, and MTBF is an average measurement of how long a system operates between failures. These distinctions are consistent with common disaster recovery and continuity planning practices referenced by industry guidance such as NIST contingency planning concepts and standard business continuity terminology.
- A. Correct.
Correct. Recovery Time Objective (RTO) is the maximum acceptable time to restore a service after an outage, so the requirement to restore the application within 2 hours is the RTO. Recovery Point Objective (RPO) is the maximum acceptable amount of data loss measured in time, so tolerating no more than 15 minutes of lost appointment data means the RPO is 15 minutes. This is a common way organizations define disaster recovery targets for critical applications.
- B. Incorrect.
Incorrect. RPO does not measure how long it takes to restore service; it measures acceptable data loss. The 2-hour requirement refers to service restoration time, which is RTO, not RPO. MTTR measures the average time required to repair a failed component or service across incidents, not the maximum acceptable data loss. Someone might choose this option by confusing operational reliability metrics with disaster recovery objectives.
- C. Incorrect.
Incorrect. MTBF is Mean Time Between Failures, which estimates the average operational time between failures of a repairable system. It is not used to define a recovery deadline after an outage. The 15-minute value in the scenario refers to acceptable data loss, which is RPO, not RTO. This distractor targets the misconception that all time-based metrics in continuity planning are interchangeable.
- D. Incorrect.
Incorrect. MTTR is Mean Time To Repair, an observed or calculated maintenance metric describing average repair duration, not a business-defined recovery objective. MTBF is a reliability metric indicating average uptime between failures, not acceptable data loss. This option reverses the purpose of both metrics and does not match the scenario's business requirements.