olemus
ISO/IEC/IEEE 24765, ISO/IEC 14764:
plaaniväline muudatus
süsteemi töövõime ajutiseks säilitamiseks
korrektiivhoolduseni
=
unscheduled modification performed to temporarily keep a system operational pending corrective maintenance

ülevaateid
https://www.roadtoreliability.com/types-of-maintenance/

https://www.fiixsoftware.com/emergency-maintenance/

https://www.onupkeep.com/learning/maintenance-types/emergency-maintenance