As with all planned maintenance on important systems, the tasks need to be
planned by the individuals performing them, so that no original thought or
problem solving should be involved in performing the task during the window.
There should be no unforeseen events but only planned contingencies
Planning for a maintenance window also has another dimension, however.
Because maintenance windows occur only occasionally, the SAs need
to plan far enough in advance to allow time to get quotes, submit purchase
orders and get them approved, and have any new equipment arrive a week
or so before the maintenance window. The lead time on some equipment can
be 6 weeks or more, so this means starting to plan for the next maintenance
window almost immediately after the preceding one has ended.