One company found that its shutdown sequence was helpful even for an unplanned
outage. The data center had a raised floor, with the usual mess of air conditioning conduits,
power distribution points, and network cables hiding out of sight. One Friday,
one of the SAs was installing a new machine and needed to run cable under the floor.
He got the tile puller, lifted a few tiles, and discovered water under the floor, surrounding
some of the power distribution points. The SA who discovered the water notified
his management—over the radio—and after a quick decision, radio notification to the
SA staff, and a quick companywide broadcast, out came the shutdown list, and the
flight director for the upcoming maintenance window did a live rehearsal of shutting
everything in the machine room down. It went flawlessly because of the shutdown list.
In fact, management chose an orderly shutdown over tripping the emergency power
cutoff to the room, knowing that there was an up-to-date shutdown list and having
an assessment of how long before water and electricity would meet. Without the list,
management would have had to cut power to the room, with potentially disastrous
consequences.