Durations appear to be changing at random

[Sherri]

Hi there,

I'm hoping there's an easy solution to this problem...all of my project
schedules appear to have the same issue.

The problem: fixed duration tasks are increasing their duration when
changes are made to (seemingly) unrelated tasks.

Example: Task A has a duration of 10 days. MS project has changed the
duration to 12.38 days. When the duration is reduced back to 10 days, a
warning message appears saying that Task X has had its duration increased to
accomodate the change made to Task A. When I investigate what has happened to
Task X, usually the duration has increased (quite significantly), say from 10
days to 26 days. When Task X is returned to its 10 day duration, the same
warning message appears for a different task, and so the domino effect goes
through the project until I've exhausted all of the tasks.

As far as I can tell, none of these tasks are directly related to one
another and there is no logical reason for a change in duration of one task
to affect the duration of another.

To add to the misery, it doesn't always warn me that it's changing a
duration elsewhere in the project.

help - it's wreaking havoc on my completion dates.

Thanks. Sherri

 

[Jan De Messemaeker]

Just a hunch... do you have automatic leveling on?

 

[Sherri]

Oooh...I wish it were that

Leveling is set to Manual.

Sherri

 

[JulieS]

Hi Sherri,

It may be an issue related to non-working time for resources. Project
will change the duration of a fixed duration task to accommodate a
change in resource calendars. If you are changing durations of Task X
and it is linked to Task A, if Task A now falls into non-working time
for a resource, the duration will change.

I hope this helps. Let us know how you get along.

Julie

Visit http://project.mvps.org/ for FAQs and more information about
Microsoft Project.

 

[Sherri]

Thanks Julie,

That's definitely part of it, the resource works a 4-day week, with 5 weeks
on and 1 week off. The calendar has been set to reflect that, but the
durations still exceed the length of time that should be scheduled even with
the non-working time factored in. For example, the duration of a task A is 6
days long, but there are 4 non-working days that fall within that time, which
should make the duration 10 days. The problem is that the duration is being
set much higher, say 17 days.

 

[JulieS]

Hi Sherri,

Does Task A fall within the 1 week off time?

I am also a bit confused when you say the "duration" of the task should
be 10 days. If I have set Task A initially as a 6 day duration task and
then assign a resource whose calendar has 4 non-working days in the
midst of the 6 days, the duration still shows 6 days, not 10. The finish
date of the task will change, but the duration still shows 6 days.

Duration is measured in working time based upon the working and
non-working time for the resource assigned.

So, when you say duration are you counting calendar days?

I hope this helps. Let us know how you get along.

Julie

Visit http://project.mvps.org/ for FAQs and more information about
Microsoft Project.

 

[Sherri]

Hi Julie,

It doesn't seem to matter whether the task falls within the week off or not,
and I've just noticed that it's ignoring some of the days off and scheduling
tasks to start or stop on those dates.

Unfortunately I can't seem to paste a screenshot of what the task details
look like, so I'll do my best to clarify what's going on.

Here's a sample of an actual task I'm trying to correct.

The task breakdown is as follows: (the workflow is for writing a document)

Task name: Work Duration Start
Finish
Writing 24.18 h 7.05 days 05/04/07
05/15/07
resources assigned: writer 77% 7.68h, reviewer 197% 16.5h (working
concurrently - 1 writer and 2 reviewers)

The task should take less than 1 day using a standard 8 hour day. The
resources are all set to 100% usage availability and the working time is set
to an 8 hour day. The reviewers assigned to the task are the ones with the
reduced schedule - every Friday and every sixth week off. May 4th and 11th
are scheduled days off. The sixth week off falls the week before this task
starts --The week ending May 4th.

The second step in this process is to prepare the document for a 3rd party
review. It is a fixed duration task as well, but when the duration for the
writing task is changed to reflect the correct duration, this next task
increases by 2 days. (fairly consistently but not every time)

I hope this makes a little more sense... (my apologies if I've made it worse
)

Sherri

 

[JulieS]

Hi Sherri,

Sorry for the delay in replying. If possible, why don't you zip the
file and send to me by email? That way I can take a look at the project
to see what you are seeing. Perhaps between the two of us looking at
it, we can work it out!

My email address is:

passport 6847 at maine dot r r dot com

Remove spaces. Convert at to @ and replace dot with .

--
I hope this helps. Let us know how you get along.

Julie

Visit http://project.mvps.org/ for FAQs and more information about
Microsoft Project.

 

[Sherri]

No worries. Thanks for the offer of help. The file is on its way to you now.
Let me know if it doesn't arrive.

Cheers. Sherri

 

[JulieS]

Hi Sherri,

File is here and I am reviewing now. I'll send you an email with
details.

Julie

Visit http://project.mvps.org/ for FAQs and more information about
Microsoft Project.

 

[Mike F]

Was a solution ever determined? Sounds like several of us have similar
issues with fixed durations changing...

Mike

 

[JulieS]

Hi Mike F,

Sherri, the original poster, had some differences in the calendar
definitions between her project calendar and the base calendar for
resources that was causing some problems. It's tough to tell what may
be causing the difficulties in your file without some additional
details.

That being said, changes in Fixed Duration tasks is frequently due to
nonworking time in the resource calendar.

--
I hope this helps. Let us know how you get along.

Julie

Visit http://project.mvps.org/ for FAQs and more information about
Microsoft Project.