Mean time to repair is an essential failure metric that represents the average time it takes to repair and restore a component or system to functionality. As such, MTTR is a primary measurement of the maintainability of an organization’s systems, equipment, applications and infrastructure, as well as its efficiency in fixing that equipment when an IT incident occurs.
MTTR begins the moment a failure is detected and encompasses diagnostic time, repair time, testing and all other activities until service is returned to end users. A low MTTR indicates that a component or service can be repaired quickly and, consequently, that any IT issues associated with it will probably have a reduced impact on the business. A high MTTR signals that a device’s failure could result in a significant service interruption and thus more significantly affect the business.
According to ZK Research, 90 percent of MTTR is spent just trying to figure out that there’s actually a problem. Incorrect diagnosis or inadequate repairs can also lengthen MTTR. A high MTTR should prompt IT administrators to reevaluate their approach to troubleshooting, taking into account the entire lifecycle, from how they monitor and detect through to how they diagnose and resolve, with the goal of reducing potential downtime.
Most service-level agreements include MTTR in some manner. It’s important to remember that MTTR represents a typical repair time, not a guaranteed one. A vendor claiming an MTTR of 24 hours is saying that’s how long it usually takes to complete a repair, but individual incidents could take more or less time to resolve.
Depending on the context in which it’s used, MTTR may also stand for mean time to recovery, mean time to resolve or mean time to resolution. In all cases, the term denotes the average time required to troubleshoot and repair an issue.