When the problem is resolved and the support ticket is updated to reflect the new status, this is considered the end of the incident.
The times reported in the ticketing system for start and end are generally used to calculate the time it took to repair the problem.
To calculate the MTTR take the total time invested in solving problems and divide this by the number of problems resolved.
Some companies implement a second level of analysis to validate the problem was truly resolved and not prematurely closed as a way of achieving individual metrics. To stop premature closure of issues to achieve team performance metrics, such events are weighted against the performance goals of the support team. This level of increased scrutiny is normal and indicative of measurement systems that strive to be customer centric and not operator centric.
Resolving problems as quickly as possible is always a KPI of support and operations teams. These teams value any innovation that truly reduces the time it takes to resolve problems.
Nastel delivers reduced MTTR by providing a consistent view of the user experience across the entire application stack allowing for rapid root cause analysis and the elimination of many of the usual war room processes. Using Nastel many customers are able to identify future events pro-actively, allowing problems to be resolved before they actually happen. This actually can be reported as a negative MTTR, which many had thought was impossible.