Serviceability
Probability of a service being completed within a given time window
If a system has a serviceability of 0.98 for 3 hours, then there is a 98 percent probability that the service will be completed within 3 hours.
In an ideal situation, systems can be serviced without any interruption of user support.
This is possible by using hot-swappable components such as power supplies, fans, disks, and system boards