To meet availability goals such as 99.999 percent, adequate error detection must be designed in, or a component may not be suitable for use in highly available systems. This process depends greatly on the definition of a fault zone. At this stage of the process, it is not necessary to locate an error to a region smaller than what will be isolated. The region that is isolated must be bounded at a point where it can be removed from all interaction with the system. Recovery also requires restoring any portions of the system that were adversely affected by the failing component.
Recovery is the final step in the process that contributes to outage time.
Once the system is providing complete service again, the remainder of the process does not directly contribute to outage time. The repair process is indirectly related to availability. In systems employing redundancy, there is a statistical possibility that a second failure can occur in the component covering for this failure, which would result in a complete system outage. While the probability is low, the severity is high enough to make this a factor in the availability equation. It is important, even in redundant systems, to keep repair times low.