One thing to note ... a milestone is not a date per se. Rather it is an
event that marks some transition in the project, a gate if you will along
the path from start to finish. They often need to occur on or before a
certain date so that event may certainly, and usually do, have a deadline,
but be very careful not to confuse the event itself with the date on which
it occurs or the deadline by which it is supposed to occur. IF I'm putting
up a building I might have a deadline of Jan 1 by shich I need to have the
foundation finished. But the milestone is the physical completion of the
foundation, the transition event making the change of status between "not
complete" and "complete" and not the date of 01 January.
A milestone is entered into Project as if it were a regular task but with a
major difference ... its duration is set to zero. It will have predecessor
tasks linked to it, the activities that have to occur in order to make the
event take place, and successors linked after it, the things that can't
happen until the milestone event has taken place. The date on which those
milestones occur, then, is driven by the dates that their predecessors allow
them to occur and like any other event or activity it may appear in the plan
ahead of, on, or after its required deadline. If the plan shows an
important milestone occuring late, after the date that's required, that's
very important information that Project is giving you - it's telling you
that it will be impossible to meet your deadlines if you proceed according
to the way you've presently organized the work and you need to rethink to
plan while there's still time to change it.
The deadlines for a milestone (or any other task) and you're 'signifigant
date' are entered by selecting the task or milestone in question, displaying
the Task Information dialog box, and on the Advanced tab above the the
contraints you'll see a Deadline entry and put the date in there. I feel
very strongly that you SHOULD NOT use a "Finish No Later Than" constraint
which at first glance seems to be the same thing - in fact a constraint is
very different thing from a deadline. The deadline shows you when the event
SHOULD occur by and where it WILL occur if you go according to your present
plan. If it will be late according to the way you've organized the work
ahead of it, Project tells you that. The constraint, OTOH, will always show
the event taking place on its required date, even if it is physically
impossible for it happen by then according to the way you've organized the
plan. Using FNLT constraints instead of deadlines essentially gives you a
Gantt chart that lies to you, promising you'll succeed even if you're going
to fail.
By the way, whether you're talking about milstones or any other tasks or
events in the project, do not set start and finish dates except in very
specific and rare circumstances. The job of scheduling software is not to
draw pretty charts of dates you've already figured out somehow. Its job is
to calculate those dates for you based on the project kick-off date, the
duration of the various tasks, the relationships between the tasks, and the
availability of assets that you assign to get the work done. It short, you
don't tell project the dates you want, it tells you the dates you can have
<grin>.
