101Overview—Types of Maintenance
a form of maintenance that is performed after a fault or problem emerges
in the system, with the goal of restoring operability. In some cases, it can be
impossible to predict or prevent a failure, making this type of maintenance
the only option.
Corrective maintenance can be subdivided into:
• Immediate corrective maintenance: Work that will begin immedi-
ately after a failure.
• Deferred corrective maintenance: Work that is delayed in confor-
mance to a given set of maintenance rules.
Corrective maintenance refers to action only taken when a system or
component failure has occurred. It is important for the maintenance of
repairs to begin as soon as possible. Costs associated with corrective main-
tenance inclu