One week before the maintenance window, the flight director freezes the
change proposals and starts working on a master plan, which takes into
account all the dependencies and elapsed and active times for the change
proposals. The result is a series of tables, one for each person, showing what
task each person will perform during which time interval and identifying the
coordinator for that task. A master chart shows all the tasks that are being
performed over the entire time, who is performing them, the team lead, and
what the dependencies are. The master plan also takes into account complete
systemwide testing after all work has been completed.
If there are too many change proposals, the flight director will find that
scheduling all of them produces too many conflicts, in terms of either machine
availability or the people required. You need to have slack in the schedule
to allow for things to go wrong. The difficult decisions about which
projects should go ahead and which ones must wait should be made beforehand
rather than in the heat of the moment when something is taking
too long and blowing the schedule, and everyone is tired and stressed.
The flight director makes the call on when some change proposals must
be cut and assists the parties involved to choose the best course for the
company.