What is Downtime?
Scheduled Downtime is a controlled event. Scheduled downtime that occurs to allow for hardware and/or software changes will be variable in duration and will depend on the amount of time required for the system to be off-line to implement changes.
Unscheduled Downtime is not a planned event. Either the system will “self-diagnose” a problem and bring the system down automatically or IS will bring the system down to correct an immediate problem. Unscheduled downtime can be attributed to several causes: power failure, air conditioning failure (in computer operations), software problems, program problems, sporadic hardware failure, network failure, and heavy system use.