“Mean time to X” is a common term used to describe how long, on average, a particular milestone takes to achieve in incident response. There’s mean time to detect, acknowledge, mitigate, etc. And then there’s the elusive “mean time to recover,” also known as “MTTR.” MTTR, a hotly debated acronym and concept, measures how long it takes to resolve an incident on average. The problem with MTTR, though, is that it doesn’t matter.