There is sometimes confusion about what milestones are. They are NOT dates
themselves but they do occur on at some specific date and time. The
milestone itself is the event that takes place - a contract has been signed,
a final report has been completed, a critical part has been delivered, a
project phase has been completed, etc - that has some special signifigance
in the project. It occurs whenever it occurs and even though there may be a
target or desired date, just like any other event the milestone event itself
might take place early, on-time, or late. In other words, you have TWO
dates associated with your milestone event - the date when it WILL occur and
the date by which it SHOULD occur. (I should point out that milestones
don't necessarily have a due date - remember the milestone is an event and
even though it's important to monitor for project tracking purposes we might
not actually care when it happens.) In engineering you could say that the
milestone marks a state change - in erecting a building before the milestone
"foundation ready" the construction of the foundation is in process. The
milestone marks the point where the foundation is complete and we can move
on to the next phase. The change of state is "foundation incomplete" ->
"foundation ready."
In your example the milestone is the receipt of the material. You need it
by Oct 15th so that is its deadline. But the delivery might come in a week
before, on the 15th, or there might be a trucker's strike and your material
might not get there until November. The date shown in the Gantt chart is
the estimated date based on links leading to it, including lag times, until
it has occured and then the actual date on which it did occur. By entering
a deadline on the Task Information sheet, Advanced tab, for the milestone
you can put a green arrowhead marker on the Gantt chart to indicate what the
"drop dead" date of the milestone is and to see whther you're making the
required schedule or not.
Moving the milestone will not move the deadline nor should it. If we had to
have parts received by 15th October last year does that mean in a similar
project next year we'll need the same delivery date? Not very likely.
--
Steve House [MVP]
MS Project Trainer/Consultant
Visit
http://www.mvps.org/project/faqs.htm for the FAQs