Project 2000- Trouble with duration, start and end date

[beena]

Hello,

I would really appreciate if someone can help me in this... I have a
task where I want the duration to be 3 months, but the start date
should be 5/1/08 and the task should end on 7/31/08.

If I keep the duration as 3 months (I have the constraint as must start
on) and the start date is 5/1/08 then I Project calculates the finish
date as 7/25/08. Please someone tell me how to keep the duration and
start and finish dates constant.

 

[beena]

Thank you for the reply.. Can you help me a little more and tell me ho
to do that. I am hearing about emonths for the first time

 

[Steve House]

Duration is a measure of the amount of working time a task requires.
Non-working time, holiday, etc don't count for duration. Also,k the default
assumption is that a month contains 20 working days, each with 8 working
hours. So when you enter a task and say it should have a 3 month duration,
Project calculates that it will require a total of 480 (3*20*8) working time
hours to do the work. You have said the task will begin on 5/1/08, I assume
at 8am. The calendar (Tools, ChangeWorkingTime) defines what hours out of
the day and week are wokring time hours. Project begins counting time
starting at 8am 5/1/08, disregards any non-working time hours, and continues
until it's counted off 480 working time hours and that's when it computes
the task will end. If you think about this makes perfect sense since a task
always represents physical activity done by a person or persons and can only
take place during the time those resources are on the property and able to
work on it.

If you enter the duration as "3 months" project will always convert that to
20 days at 8 hours per day. If you enter it just like that the above
discussion will be true. There is another way to specify time and that is
by 'Elapsed Time.' Elapsed time disregards the calendar and assumes that
the task proceeds without interuption from start to finish. You enter it by
putting "e" in from to the time unit - ie, "24H" is 24 duration hours but
"24EH" is 24 Elapsed Hours. At task starting Monday at 8am with "24H" as
its duration will end Wednesday at 5pm. Another task starting at the same
time, 8am Monday, but with it's duration shown as "24EH" will end Tuesday at
8am. So to get your 3 calendar month task duration, enter it as "3 emonths"

HTH

 

[John]

All,

My apologies for inserting this question in someone else's question thread,
but I haven't been able to get this board's "new thread" functionality to
work. So...

Where does one set up a project so that the project is tracked on a
work-based approach (rather than an effort-driven approach)? Can the
work-based approach be adopted after a project has been set up with an
effort-driven approach and time units already enered for duration for each
subtasks?

Thanks

ksmorris,
No problem tacking onto another post. At least you let us know why and
we appreciate that.

Project has three types of tasks - fixed duration, fixed work and fixed
units (i.e. resources). Fixed duration and fixed units can be either
effort-driven or non effort-driven. Fixed work is by default
effort-driven. When a new project is developed both the task type and
the effort-driven options can be set under Tools/Options/Schedule tab.
The default is Fixed Units and effort-driven.

Tasks in an existing project can always be modified to another task type
by going to Project/Task Information/Advanced tab. However if effort on
a task has already begun (i.e. the task has started), changing the task
type must be done with care to avoid unexpected results.

What you said in your last sentence makes me think you may not fully
understand the difference between duration and effort in Project.
Duration is the time during which a task will be performed. It is simply
the amount of working time between the task start and task finish. Work
on the other hand is the estimated effort one or more resources will
expend actually performing the task. If a single resource is assigned
full time then, and only then will the Duration field and the Work field
be equal.

The bottom line is that it sounds like what you want is fixed work type
tasks. Project will then hold work constant while duration and units
will vary according to Project's work equation:
Duration = Work/Units

You might want to read more about "task types" in the Project help file.
It explains how Project calculates the work equation in different cases.

John
Project MVP

 

[ksmorris]

John,

I've been reading the Microsoft paper "Create a Project Plan in 5 Easy
Steps"
(http://office.microsoft.com/en-ca/project/HA011361531033.aspx#Step 1 ).

If I have a shcedule that is driven by regulatory deadlines (i.e., specific
data must be calulated and reported to a regulatory oversight board by X
date) certain of my tasks must be completed by a specific business day in
order to be submitted to the next (dependent) step so that the ultimate
regulatory filing submission date is satisfied. Therefoe, it would seem I'd
want to set up the project such that each step along the way to satisfying a
regulatory filing submission date has a fixed end date (i.e., it must be
completed by a specific date in order for the next step or dependency to
occur on time). Somewhere in the article I was reading, I thought I read
that there are two scheduling approaches: 1) work-based or "effort-driven"
(in which one enters the amount of hours that will be required to complete
the tasks. The assignment of resources to these tasks causes the Duration
(i.e., the elapsed time it will take to complete the tasks) to be calculated,
and 2) duration-driven approach, which is strictly a scheduling approach
(i.e., elaped time to perform work is pre-set by setting duration for the
task and then resources are assigned to the task). I'm not really clear on
this latter approach (it sounds as if you have a task in a duration-driven
approach, and your duration is pre-set to 3 days, you simply assign the
appropriate staff to the task for the hours the duration requires?).

From what you've said, I would use a "Fixed Duration" setting for the Tasks,
if I wanted to use a Duration-driven approach (i.e., set the duration and
then assign enough resources to satisfy the duration time requirement). And
if I wanted to use an effort-driven approach (the default in Project), I
would use a "Fixed work" setting for the tasks, then assign my resources, and
Project would tell me when each task would be completed (based on how many
resources I assigned and at what % committment).

I probably am a bit unclear about the two scheduling approaches. I'd
appreciate any clarity you can bring to my understanding, perhaps by stating
how each of these two scheduling approaches would impact the
regulatory-deadline-based project I mentioned.

I very much appreciate your thoughtful responses.

 

[Steve House]

Adding a note to John's post, in MS Project "Work" and "Effort" mean pretty
much the same thing. The work metric expressed in the units of man-hours is
a measure of the amount of effort that needs to be expended by the resources
in order to create the task's required outcome.

 

[ksmorris]

Steve,

Ah, thanls. Therefore, a work-driven approach would be when one uses a
fixed-work setting for all of the tasks (this is tge default), and a
Duration-driven approach would be when one uses a fixed-duration setting for
all of the tasks (this is not the default and is used strictly for
scheduling)?

Adding a note to John's post, in MS Project "Work" and "Effort" mean pretty
much the same thing. The work metric expressed in the units of man-hours is
a measure of the amount of effort that needs to be expended by the resources
in order to create the task's required outcome.
--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs

All,

My apologies for inserting this question in someone else's question
thread,
but I haven't been able to get this board's "new thread" functionality to
work. So...

Where does one set up a project so that the project is tracked on a
work-based approach (rather than an effort-driven approach)? Can the
work-based approach be adopted after a project has been set up with an
effort-driven approach and time units already enered for duration for each
subtasks?

Thanks

 

[Steve House]

IMHO you don't create a project plan to document what the requirements are.
Rather, you create the plan so you have a computational model to help you do
"what-if's" in order to figure out just how you have to arrange the work so
you can meet those requirements. As such, it always needs to show you the
results of your trials, be they good or bad, until you figure out the plan
that meets your objectives. That way you can proceed with reasonable
confidence that if we work according to this particular plan, we will meet
our regulatory filing requirements, or put more generically, we'll meet the
required delivery schedule of our deliverables.

The end date of a task is not the date that it is required to be completed
by, it is the date that it will be completed by if you start the task on the
scheduled date and work it with the present resource assignments. The
required date is a deadline and the expected finish may be on, before, or
after the required date. The start date is determined by when any
predecessor tasks producing components that the task in question requires
have been completed and when the resources with the necessary qualifications
to do the work become available. If you leave the task unconstrained and do
NOT try to specify the finish date, Project will show you the date that it
will probably complete if it starts and you work it with what the present
plan shows as happening with those two factors. . If after plugging in
everything it turns out that estimated finish date is after the required
finish date, you have basically two choices - either start the task earlier
by getting its predecessors to finish earlier, or work it faster, increasing
the resources committed to the task so that once it starts it will be
completed in a shorter amount of time. But you can't use a fixed finish
date to declare that it will finish on a certain date and expect that
declaration to be sufficient to make it really happen.

The duration driven approach comes from the way estimates are often done.
When you estimate, you have to have data to base it on, you can't just pluck
numbers out of thin air to make the schedule fit into a preconceived notion
of what it needs to look like. If you're estimating what will be required
to complete a certain task, one way is to look at the history of when you've
done similar tasks in the past. Work driven estimating requires you have
timecard or similar data so you can see the actual man-hours that were
required to produce 100 widgets in the project we did last year. But that
level of historical detail is often not available. What is more likely
available is history showing that we had 3 guys working on it and it took
them 2 weeks to do it along with subject matter experts who can look at a
vacant lot and tell you "Yep, it'll take us about 3 weeks to dig out the
hole for the foundations." Estimates based on work effort are probably
more accurate but estimates based on duration are probably going to be a lot
easier to come by.

HTH

 

[Steve House]

Actually the most common approach is the default "fixed units" setting.
This models the fact that you usually only have X-number of resources to
assign to your project and when you assign them you expect them to give
their work their full attention, thus the level of commitment becomes a
relatively fixed quantity and acts as the primary constraint on the possible
schedules. Fixed Duration is IMHO an incredibly rare occurance and vastly
over-used in preparing schedules. It's tantamount to saying "I want this
task to take 3 weeks and so that is what I'm going to force it to be in the
schedule." No, it doesn't work that way except for tasks such as, say, a
timed stress test of a prototype that has to run for an exact period of
time, no more and no less. Most tasks the duration is a variable that
depends on the relationship between the AMOUNT of effort required (Work) and
the RATE at which effort can be generated (Resource Assignment). Fixed
Duration says the desired duration is a driving force but I think most of
the time it really is a consequence rather than a cause. OF course, the
task types in Project only kick in to affect what gets held constant and
what gets recalculated when you edit one of the three terms in the task
equation W=D*U - if you're not editing an assignment, either directly or
indirectly, they have no effect. If you have a task type of Fixed Units and
you do in fact edit the Units, it will default over to behave as if it was
Fixed Work for the purpose of that one calculation pass.

HTH

--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs

Steve,

Ah, thanls. Therefore, a work-driven approach would be when one uses a
fixed-work setting for all of the tasks (this is tge default), and a
Duration-driven approach would be when one uses a fixed-duration setting
for
all of the tasks (this is not the default and is used strictly for
scheduling)?

Adding a note to John's post, in MS Project "Work" and "Effort" mean
pretty
much the same thing. The work metric expressed in the units of man-hours
is
a measure of the amount of effort that needs to be expended by the
resources
in order to create the task's required outcome.
--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs

All,

My apologies for inserting this question in someone else's question
thread,
but I haven't been able to get this board's "new thread" functionality
to
work. So...

Where does one set up a project so that the project is tracked on a
work-based approach (rather than an effort-driven approach)? Can the
work-based approach be adopted after a project has been set up with an
effort-driven approach and time units already enered for duration for
each
subtasks?

Thanks

:


Hello,

I would really appreciate if someone can help me in this... I have a
task where I want the duration to be 3 months, but the start date
should be 5/1/08 and the task should end on 7/31/08.

If I keep the duration as 3 months (I have the constraint as must
start
on) and the start date is 5/1/08 then I Project calculates the finish
date as 7/25/08. Please someone tell me how to keep the duration and
start and finish dates constant.


--
beena
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