There is only a limited amount of mind-reading that Project can do for you.
You've said your task is a fixed duration task. The duration is the number
of working time units between when work is first performed and when it ends.
"Fixed duration" for a 5 day task that is presently starting on Monday does
not mean regardless of when it starts it will always end on Friday - it
means that whenever it starts it will always finish 5 days later. My task
is to assmble 50 widgets and I can assemble 10 widgets a day. If I start on
Monday, I'll finish the last widget on Friday, 5 days later. But if I get
delayed and don't start until Wednesday, that doesn't mean I only have to
assemble 30 widgets - I still have to do 50 and I still can only do 10 per
day. So the finish date has to change to the following Tuesday because
that's when my 5 days of duration will pass after the start on Wednesday AND
that really is the earliest possible date that I could finish all 50 of the
widgets I'm required to assemble in order to complete the Project's
deliverable. If your task is to do 150 widgets and you assign 3 resources
to it, that means each resource will do 50 widgets. Whether they work
together or separately, each resource will be required to do 50 widgets.
99% of the time that is an accurate description of the physical nature of
the work and Project has no way of knowing if this is one of the 1% that are
the exception.
A second misconception evident in your post is just what the task type means
and where it has some effect. Fixed duration, fixed work, and fixed units
all refer to the identity W=D*U that is at the core of all Project's
resource calculations. Remember your basic high school algebra - any linear
equation (y=mx+b) such as this one has a constant, an independent variable,
and a dependent variable. You change the independent variable and the
equation calculates the dependent variable. In Project, "b" is zero and
so the equation is "y=mx". Project lets you pick what term is the constant,
the "m", and what term is the independent variable, the "x". When you're
editing a resource assignment, that is changing one of the terms Work,
Duration, or Units, the item you are changing is the independent variable
and the task type setting instructs Project what to hold constant. If
you're changing Units and you want MSP to recalculate work, set the task to
fixed duration. If you're changing the Units and want Project to
recalculate the duration, set the task type to fixed work. If you're
changing the Units and the task type is left on Fixed Units (the default)
Project behaves as if the type were Fixed Work this go around. But if
you're NOT changing one of the values W, D, or U for resource assignments
that have already been made, the task type setting has absolutely no effect
whatsoever. In your "problem" example, you weren't changing any of those
values when you change the date he starts on the task - the work he's
required to do is the same, the duration for your resource is the same, and
the units he's assigned are the same - you've merely delayed the start date
when he begins to assemble his 50 widgets. And this is crucial to remember,
as far as these computations are concerned, Project doesn't know that any
other resources assigned to the task even exist.
When you have multiple resources each of them is considered to be
independent of all the others and the task duration shown on the Gantt chart
is measured from the time the earliest starting resource begins until the
latest finishing resource is done. But the W=D*U formula looks at each
individual resource in a vacuum. If Joe, Bill, and Fred are all scheduled
to start together and work for 10 days, then Bill is delayed a few days, Joe
and Fred will start their 10 together and Bill will come in a couple of days
after. After Joe and Fred have done their 10 days they go away. Fred
continues work by himself after they're gone until he's done his 10 day fair
share of the work. The durations for each resource's task have not changed,
they're each working for 10 days at 100% doing 1/3 of the total output of
the task, just like before and so task type settings have no effect at all,
there's nothing to recalculate. What has changed is the total time between
when the early bird gets started and the slow bird finishes, ie, the date
when all the required work of the task finally gets done. Anything else is
going to require hand adjustments on your part.
--
Steve House [MVP]
MS Project Trainer & Consultant
Visit
http://www.mvps.org/project/faqs.htm for the FAQs
DaveFusion said:
I thought of that it just seemed to be a lot of work for something I
thought
MSP could do by itself - I take it therefore that there is no way to tell
MSP
to adjust the work to fit theduration for a resource.
i.e. if date1 to date2 > 50 days [working] and units = 100%, then work
will
also = 50 days, rather than changing date2 to accomoate the work amount
that
I don't want.
Jan De Messemaeker said:
Hi,
If you want Work to change, then change it
)
Go to task usage view, and start inputting zeros in for Work the first
days
of the assignment
HTH
--
Jan De Messemaeker
Microsoft Project Most Valuable Professional
http://users.online.be/prom-ade/
+32-495-300 620
DaveFusion said:
I've got a fixed duration task with a number of resources allocated,
the
dates for this task are 1/4/05 to 31/3/06.
If I add a new resource to this task, it initially assumes the 'task' dates
in the Task Usage view.
However when I want to change the 'start' date for that resource, MSP
retains the 'work' value and insists on moving the date for the
resource [
and the task ] out to a later date.
I've tried using 'restraints' but that does not work either.
How can I tell project that an end date is an end date and it should
re-caluclate the 'work' value for a resource not change the dates.
Thanks for any help on this ; )
