Editing Maintenance (section)

====Planned maintenance====
{{redirect|Routine maintenance|the album by Aaron West and the Roaring Twenties|Routine Maintenance (album)}}
Planned preventive maintenance (PPM), more commonly referred to as simply '''planned maintenance''' ('''PM''') or '''scheduled maintenance''', is any variety of scheduled [[Corrective maintenance|maintenance]] to an object or item of equipment. Specifically, planned maintenance is a scheduled service visit carried out by a competent and suitable agent, to ensure that an item of equipment is operating correctly and to therefore avoid any unscheduled breakdown and downtime.<ref>{{cite book | last1 = Wood | first1 = Brian | title = Building care | publisher = Wiley-Blackwell | year = 2003 | url = https://books.google.com/books?id=xi6e4KhRoPwC | access-date = 2011-04-22 | isbn = 978-0-632-06049-8}}</ref>

The key factor as to when and why this work is being done is timing, and involves a service, resource or facility being unavailable.<ref name="Downtime.mil" /><ref name="Upgrade.gov" /> By contrast, condition-based maintenance is not directly based on equipment age.

Planned maintenance is preplanned, and can be date-based, based on equipment running hours, or on distance travelled.

Parts that have scheduled maintenance at fixed intervals, usually due to wearout or a fixed [[shelf life]], are sometimes known as time-change interval, or TCI items.