Which operational metric to measure the health of the incident management process is critical?

C.

The operational metric that is critical to measuring the health of the incident management process is the mean time to restore service, also known as MTTR.

MTTR is the average time taken to restore a service after an incident has occurred. It measures the efficiency and effectiveness of the incident management process in identifying, diagnosing, and resolving incidents. The shorter the MTTR, the better the incident management process is performing.

MTTR can be broken down into several components, including the time it takes to detect an incident, the time it takes to diagnose the root cause, and the time it takes to implement a fix. By analyzing these individual components, organizations can identify areas for improvement in their incident management process.

While the other metrics listed in the answer choices (mean time to resolve incidents, number of incidents per severity level, and number of successful changes) can be useful in measuring the performance of an incident management process, they do not provide as complete a picture as MTTR. For example, mean time to resolve incidents only measures the time taken to resolve an incident, not the time taken to restore service. Similarly, the number of successful changes measures the success of the change management process, but not the incident management process.

In summary, MTTR is the most critical operational metric to measure the health of the incident management process. It provides a comprehensive view of the process's performance and identifies areas for improvement.