Available Embedded Computer Platforms Become Reality Tutorial 3. These definitions apply equally to hardware and software components of a system. Detection is defined as the time from a failure causing a loss of service to the system becoming aware of it.
Error detection is the responsibility of every hardware and software component in the system.
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.