[t]he practice of periodically performing maintenance activities on a system or equipment with the intended purpose of preventing unscheduled outages of the equipment due to component failure.[1]
”
“
[a]ll actions performed in an attempt to retain an item in a specified condition by providing systematic inspection, detection, and prevention of incipient failures.[2]
↑Department of the Army, Supervisory Control and Data Acquisition (SCADA) Systems for Command, Control, Communications, Computer, Intelligence, Surveillance, and Reconnaissance (C4ISR) Facilities, at B-4 (Jan. 21, 2006) (full-text).