Duration not working correctly

[tshad]

I have the following project with only Summary Tasks showing. Project is
the Summary task for all the other Summaries. The Summaries, as you can
see, are linked to the Summary above them.

Each task in each summary is linked to the task before it. The 1st task in
each summary is never linked to any task. I assume this is because the
Summary record is linked to the previous summary (except the 1st one). I
can't link the Summary Task "Design" to "Project because it gets an error
message "You can't link a summary task to one of it's summary tasks".

The problem is that the Summary Task "Project"s Duration isn't being updated
when I change any of the tasks' duration in "Design" - which it should. If
you add all the durations up they don't equal 40.5.

Also, if you notice the start date of Development is 2/6/07 but the ending
date of Design is 2/13/07. The other summaries work fine.

1 Project 40.5 days 50% Thu 2/1/07 Thu 3/29/07
2 Design 8.1 days 28% Thu 2/1/07 Tue 2/13/07
10 Development 22.5 days 100% Tue 2/6/07 Thu 3/8/07 2
26 Testing 10 days 0% Fri 3/9/07 Thu 3/22/07 10
37 Deployment 4.5 days 0% Fri 3/23/07 Thu 3/29/07 26

Here are the tasks in "Design" (I took out most of the name for display
purposes). Notice that there is predecessor for task #3. This is the same
for all the Summarys but the others work fine.

3 Decide 0.9 days 100% Thu 2/1/07 Thu 2/1/07
4 Decide 0.1 days 100% Thu 2/1/07 Thu 2/1/07 3
5 Decide 1 day 100% Fri 2/2/07 Fri 2/2/07 4
6 Decide 0.1 days 0% Mon 2/5/07 Mon 2/5/07 5
7 Decide 3 days 0% Mon 2/5/07 Thu 2/8/07 6
8 Decide 2 days 0% Thu 2/8/07 Mon 2/12/07 7
9 Decide 1 day 0% Mon 2/12/07 Tue 2/13/07 8

What would cause this problem?

Thanks,

Tom

 

[Rod Gill]

Design is a sub-project of Project so it cannot be linked to it.

Durations are not meant to add up. A duration is a period of time within
which all work for the task(s) get done. If you view the work table then the
total work does add up (assuming calculation is automatic). Two tasks that
overlap produce a duration that spans from the earlier start to later
finish. This is by design and the preferred way of doing things.

So, your next learning goal is to read help on work and assigning resources.
Good luck!

--

Rod Gill
Project MVP

NEW!! Project VBA Book, for details visit: http://www.projectvbabook.com

 

[tshad]

Design is a sub-project of Project so it cannot be linked to it.

Durations are not meant to add up. A duration is a period of time within
which all work for the task(s) get done. If you view the work table then
the total work does add up (assuming calculation is automatic). Two tasks
that overlap produce a duration that spans from the earlier start to later
finish. This is by design and the preferred way of doing things.

Durations do add up on all the other Summarys. And the "Project" Summary
task is adding up - just not correctly. I assume this has to do with the
Date problem between "Design" and "Development" in my project. The Duration
on Project is a calculated amount (which was a problem in one of my older
posts where it was showing a ?).

There is no overlap - that I can tell. I have all the tasks linked to the
task before it so there is no overlap.

Tom

 

[Rod Gill]

If there is no overlap - at all, then durations may add up, but they are not
meant to. On 99.9% of projects of any size (say 100+ tasks) there is overlap
so duration will not add up. It is a big mistake to rely on it adding up,
instead you need to start using work.

Your dates suggest there is an overlap? Design finishes Feb 13, Development
starts Feb 6, therefore Project is probably calculating duration correctly?

--

Rod Gill
Project MVP

NEW!! Project VBA Book, for details visit: http://www.projectvbabook.com

 

[tshad]

If there is no overlap - at all, then durations may add up, but they are
not meant to. On 99.9% of projects of any size (say 100+ tasks) there is
overlap so duration will not add up. It is a big mistake to rely on it
adding up, instead you need to start using work.

If there is no overlap then it should add but and that is what it is
obviously trying to do and does work for the other Summary Tasks (except for
"Design"). So there is obviously something wrong with this group.

It is obvious that there is a problem if you look at the Tasks for Design.
The Dates don't work correctly. Something must be cause this. I am sure it
is something I did - I just can't figure out what it is.

Your dates suggest there is an overlap? Design finishes Feb 13,
Development starts Feb 6, therefore Project is probably calculating
duration correctly?

Right, but where is it???

If you look at the Precedences they are all dependant on the task before
it - so how can there be an overlap?

Why would the Summary Start Date start at 2/6/07. There is no task that
ends on that date in the previous group. Task # 3 has a duration of 3 and
goes from 2/5/07 to 2/8/07 as you can see from my example. So there is no
2/6/07. So why would the Summary start there???

Thanks,

Tom

 

[Rod Gill]

What do you mean by the dates don't work properly?

From your data I see that Design should finish when it does, so there is an
overlap between design and development so the project tasks should NOT add
up?

--

Rod Gill
Project MVP

NEW!! Project VBA Book, for details visit: http://www.projectvbabook.com

 

[tshad]

Found the problem. But am not sure how to fix it. I hope there is a way to
deal with it.

If you do any work on a task, that tasks Start Date is locked. Therefore
all other dates that follow will be dependant on that date.

This is a real problem if I want to add some more tasks or change a duration
of a task or add a new task that is before a task that has some work done
it.

In my case, I am not really concerned with Start Dates other than to
calculate the Duration of a project. I have about 3 or 4 project I am
working on where priorities change and the date that a project finishes is
not important to us. All I am doing is looking at Duration and %Work
Completed (at the moment).

I would like to be able to add a task in the middle of a project or change a
duration and have the program recalculate the duration correctly. I can
solve the problem by zeroing out all the % Work completed to get it to
recalculate - which it does automatically. The problem is I now have to go
back and re-add in the %Work Completed that I just took out - just to
recalculate the Duration.

Is there a setting somewhere that says to recalculate even if work is done
on the tasks?

Thanks,

Tom

 

[John]

If there is no overlap then it should add but and that is what it is
obviously trying to do and does work for the other Summary Tasks (except for
"Design"). So there is obviously something wrong with this group.

It is obvious that there is a problem if you look at the Tasks for Design.
The Dates don't work correctly. Something must be cause this. I am sure it
is something I did - I just can't figure out what it is.


Right, but where is it???

If you look at the Precedences they are all dependant on the task before
it - so how can there be an overlap?

Why would the Summary Start Date start at 2/6/07. There is no task that
ends on that date in the previous group. Task # 3 has a duration of 3 and
goes from 2/5/07 to 2/8/07 as you can see from my example. So there is no
2/6/07. So why would the Summary start there???

Thanks,

Tom

Tom,
Pardon me for jumping in but did you check your calendars? If one of the
tasks in Design has a calendar that is out of sync with the project
calendar, you could get the results you are seeing.

I agree with Rod 100%. You should NOT be counting on duration adding up
in a linear fashion. That is not the intent of the Duration field.
However if you have looked high and low and simply cannot figure it out,
send me the file via e-mail at the address below and I'll take a look at
it if I have time. But, be prepared to take some flack for asking me to
find something that isn't really a problem.

John
Project MVP
jensenj6atatcomcastdotdotnet
(remove obvious redundancies)

 

[tshad]

What do you mean by the dates don't work properly?

From your data I see that Design should finish when it does, so there is
an overlap between design and development so the project tasks should NOT
add up?

????

"Design" ends on 02/13/07.

"Development starts on 02/06/07 (7 days before Design ends). Design takes
8.1 days starting from 2/01/07. Even if you take out the Weekend you should
start on about 02/09/07.

I did find out the problem, however. As I talk about in my other post, that
you probably didn't see yet, the problem is that I had addes some tasks in
my Design group after I had done some work on my first task in the
"Development" group. That locked the date to 02/06/07. So when I changed
the duration and added some tasks that should have pushed the date to a
later date - it didn't.

I need to find out how to get it to recalculate for my purposes - which I
can do by zeroing out the %Work Completed" column of each task. It will
then recalculate. I then have to reput in my %work completed. A pain in
the a__, but it does what I need. I am hoping there is a setting that says
to recalculate tasks that have work on them.

Thanks,

Tom

 

[tshad]

I did find out that what is the problem is if the task is marked as
finished. This apparently fixes the date.

I also found that on some tasks when I made the %Work Completed = 100% it
will mark it as completed. On others it won't. Not sure why. The ones
that are not marked as completed seem to be the ones that won't change the
Start Dates and End Dates (and hence the Duration). Once it has been
Completed, even if I change it to 50%, it still won't change the Start Date
but if I change it to 0% - it does. But the Summary Task Start date doesn't
change to reflect the change.

Tom,
Pardon me for jumping in but did you check your calendars? If one of the
tasks in Design has a calendar that is out of sync with the project
calendar, you could get the results you are seeing.

I agree with Rod 100%. You should NOT be counting on duration adding up
in a linear fashion. That is not the intent of the Duration field.
However if you have looked high and low and simply cannot figure it out,
send me the file via e-mail at the address below and I'll take a look at
it if I have time. But, be prepared to take some flack for asking me to
find something that isn't really a problem.

It isn't just the Duration. The Start Dates and End Dates don't change, as
I mention above. Also when I set a task to 100% it may or may not mark it
as completed. Not sure why.

Thanks,

Tom

 

[Rod Gill]

I think you are setting yourself up for a considerable amount of manual work
and frustration doing what you are. Reality says many tasks will and do
overlap. Tasks should be updated by setting actual start, then actual
duration then finally updating remaining duration. This is accurate and
shows what actually happened and provides a base on which to schedule what
should happen next.

Good luck

--

Rod Gill
Project MVP

NEW!! Project VBA Book, for details visit: http://www.projectvbabook.com

 

[tshad]

I think you are setting yourself up for a considerable amount of manual
work and frustration doing what you are. Reality says many tasks will and
do overlap. Tasks should be updated by setting actual start, then actual
duration then finally updating remaining duration. This is accurate and
shows what actually happened and provides a base on which to schedule what
should happen next.

That may be the case. But I am not interesting in actual start dates. I am
just tracking the projects progress, not by actual dates but by work done.
So I only care about Start and End Dates insofar as they affect Duration.
The only reason it doesn't work is because some dates are becoming fixed -
which I don't want, some tasks are not being marked as Completed when they
are (as I show in my other post) and %Work Completed is showing as 100% done
when it isn't.

I understand that tasks do overlap but in my scenario that isn't important.
I am finding inconsistancys in the program (which I am sure is something I
am not setting) - but the %Completed being incorrect is a real problem. If
I can't use the %Work Completed column then it is really worthless to me. I
don't want to use the Timesheets to track work done as it doesn't apply
here.

Thanks,

Tom

 

[Jan De Messemaeker]

In this part of tthe program, there are no inconsistencies.
It may not work the way you want, but is is absolutely consistent in its
calculation rules.

 

[John]

I did find out that what is the problem is if the task is marked as
finished. This apparently fixes the date.

I also found that on some tasks when I made the %Work Completed = 100% it
will mark it as completed. On others it won't. Not sure why. The ones
that are not marked as completed seem to be the ones that won't change the
Start Dates and End Dates (and hence the Duration). Once it has been
Completed, even if I change it to 50%, it still won't change the Start Date
but if I change it to 0% - it does. But the Summary Task Start date doesn't
change to reflect the change.

tshad,
Well yes, as soon as a task has any value other than "NA" in the Actual
Start field, then the Start field of that task is fixed to that date, as
well it should be. Nothing strange there.

As far as a task not being 100% complete even though its work content is
100% complete, take this example. Let's say we have a fixed duration
task with 10 days duration. We assign Joe to work the task and Joe's
calendar says that he is only available for 5 of those 10 days. Now set
the % Work Complete to 100%. You will notice that the % Complete field
only shows 50%. That is because % Complete measures duration progress
and % Work Complete measures work progress. That's why Rod said you
should be tracking work, not duration.

With regard to the summary line start date. We said it many many times
in this newsgroup, but I guess it needs to be stated one more time. The
start date of a summary line is the start date of the earliest task
under that summary and the finish date is the latest date under that
summary.

John
Project MVP

 

[Steve House]

But there is an overlap. Design isn't expected to end until the 13th while
Development shows it's already started on the 6th. That's 7 calendar days,
typically 5 duration (ie, working) days overlap.

 

[Steve House]

You're post says thet there has been some work done on the Development task.
It shoiws the 6th as the start date because when you posted in actual
progress you told it that the work began on the 6th. Project will take you
at your word that any actuals entered really do describe historical physical
facts.
--
Steve House [Project MVP]
MS Project Trainer & Consultant
Visit http://www.mvps.org/project/faqs.htm for the FAQs


....

 

[tshad]

In this part of tthe program, there are no inconsistencies.
It may not work the way you want, but is is absolutely consistent in its
calculation rules.

Actually, it isn't as I mentioned in my other post. But that seems to be a
difference in the pre-SP2 update vs post-SP2 update.

I just have to use %Completed vs %Work Completed.

Thanks,

Tom

 

[tshad]

tshad,
Well yes, as soon as a task has any value other than "NA" in the Actual
Start field, then the Start field of that task is fixed to that date, as
well it should be. Nothing strange there.

Not saying it is strange. Just that fixing the date messes up what I am
trying to achieve (which may not be possible in Project - or at least not
simple). As I mentioned before Dates are not important to me but they are
important in calculations and in building the Gnatt Graph.

Just out of curiosity, does the Graph in the Gnatt display show Estimated
Start Date or Actual Start Date?

As far as a task not being 100% complete even though its work content is
100% complete, take this example. Let's say we have a fixed duration
task with 10 days duration. We assign Joe to work the task and Joe's
calendar says that he is only available for 5 of those 10 days. Now set
the % Work Complete to 100%. You will notice that the % Complete field
only shows 50%. That is because % Complete measures duration progress
and % Work Complete measures work progress. That's why Rod said you
should be tracking work, not duration.

This may be the case. But it was working differently before SP2 as can be
seen in my other posts.

Now, the %Work Completed doesn't seem to do anything at all. If I put 100%
in a task (from the Gnatt Chart) in the %Work Completed column - The Summary
Task doesn't not show anything - neither does the Task Information windows -
nor does the Graph. If I make the changes in the %Completed, all three are
affected. This was not the case pre SP2. What is interesting is that if
the task was in my Project before I applied the SP2 update, then %Work
Completed does affect all 3. I know this is the case, as this was what I
used to use to track my progress. Now I can't.

With regard to the summary line start date. We said it many many times
in this newsgroup, but I guess it needs to be stated one more time. The
start date of a summary line is the start date of the earliest task
under that summary and the finish date is the latest date under that
summary.

I understand that. But my confusion wasn't the Summary Start Date but the
Task in the 2nd Summary that was showing as Starting before the end of the
1st Summary. And that was because I hadn't realized that the the Date was
being fixed and then I added a few tasks to the 1st summary group which
increased the End Dates but left the Start Date the same in the 2nd Group
(obviously before End Date of the 1st group).

Thanks,

Tom

 

[tshad]

But there is an overlap. Design isn't expected to end until the 13th
while Development shows it's already started on the 6th. That's 7
calendar days, typically 5 duration (ie, working) days overlap.

I agree there is an overlap - but that occurred because the date got fixed,
which I didn't understand was happening and don't want to happen. But
apparantly don't have a choice here.

I understand that in most cases that would be expected and wanted. But in
my case it isn't. The Start Date and End Dates are not important - just the
amount of work on the task completed (not when they were done).

I know how to fix the problem, now that I know what is happening, even if a
little more work.

Thanks,

Tom

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

Durations do add up on all the other Summarys. And the "Project" Summary
task is adding up - just not correctly. I assume this has to do with the
Date problem between "Design" and "Development" in my project. The
Duration on Project is a calculated amount (which was a problem in one of
my older posts where it was showing a ?).

There is no overlap - that I can tell. I have all the tasks linked to
the task before it so there is no overlap.

Tom

 

[John]

Not saying it is strange. Just that fixing the date messes up what I am
trying to achieve (which may not be possible in Project - or at least not
simple). As I mentioned before Dates are not important to me but they are
important in calculations and in building the Gnatt Graph.

Just out of curiosity, does the Graph in the Gnatt display show Estimated
Start Date or Actual Start Date?
This may be the case. But it was working differently before SP2 as can be
seen in my other posts.

Now, the %Work Completed doesn't seem to do anything at all. If I put 100%
in a task (from the Gnatt Chart) in the %Work Completed column - The Summary
Task doesn't not show anything - neither does the Task Information windows -
nor does the Graph. If I make the changes in the %Completed, all three are
affected. This was not the case pre SP2. What is interesting is that if
the task was in my Project before I applied the SP2 update, then %Work
Completed does affect all 3. I know this is the case, as this was what I
used to use to track my progress. Now I can't.


I understand that. But my confusion wasn't the Summary Start Date but the
Task in the 2nd Summary that was showing as Starting before the end of the
1st Summary. And that was because I hadn't realized that the the Date was
being fixed and then I added a few tasks to the 1st summary group which
increased the End Dates but left the Start Date the same in the 2nd Group
(obviously before End Date of the 1st group).

Thanks,

Tom

Tom,
Estimated dates become fixed when a task starts and finishes. The Start
and Finish fields in Project are dynamic - up to a point. That point
being reality. Once a task has actually started, the start date is no
longer an estimate. This emulates the real world so if that process does
play with what you want to do, then Project isn't the application you
want. Maybe what you really want are the baseline dates. Baseline dates
preserve the original plan so progress to the original plan can be
measured.

As far as what date applies to the Gantt bar, well that depends on how
the bar styles are formatted (Format/Bar Styles). The default Gantt bar
format is for bars to start on the date in the Start field, which is the
estimated start date. However, as I said before, once the task actually
starts, Project adjusts the Start field to equal the Actual Start field.

Service Pack 2 (SP2) for Project 2003 was released to resolve several
glitches with the application. If you happen to like the way Project
2003 worked before SP2, then you are definitely not using Project as it
was designed so don't expect it to act the way you want.

John
Project MVP