Calculate Duration

[Tor Gunnar]

I do have a task where I do not want to set neither duration or start or end date, but let this be calculated dynamic based on that the task should start and end in relation to some other tasks. When I set the predecessors of the the task, start-to-start and finish-to-finish, I do get the timeframe the task should be within, but it does not calculate the actual duration of the task. An example of this would be for instance an quality assurance task, starting when a mobilisation task start and ending with the final delivery. Thanks in advance!

 

[David Hunsberger]

Tor --

First, it sounds like you are describing a hammock task.
Have a look at Knowledge Base article 141733. The
Knowledge Base as you may already know is a rich library
of bug fixes and workarounds, as well as a resource for
explaining certain techniques in all MS applications, such
as Project. It can be found on the MS Web site, in the
support options list.

An alternative to using the techniques in that article is
to create a summary task with two milestones under it, the
first driven by the predecessor, and the other driven by
the successor. For these milestones it does not matter if
the link type is SS, FS, or FF. This parent task will
expand or contract its duration depending on the dynamic
dates of the milestones.

Your question was about the duration. If you use the
parent task approach above, the duration should already be
correct on the parent, and you can even take the
controversial approach of assigning resources to this
parent, although most schedulers regard that as a no-no.
If you use the hammock approach, try changing the task
type to fixed duration as opposed to the default task type
of fixed units. Under some circumstances, notably split
tasks, you will get a different value for duration when
you change the task type, even though the start and end
dates are the same! My recollection is that fixed
duration tasks measure total start-to-finish duration in
working days, while fixed units tasks measure total
*worked* duration in working days, excluding any splits
where no work is being done.

Regards,
David Hunsberger
Microsoft Project Instructor
www.it7.com
(e-mail address removed)

-----Original Message-----
I do have a task where I do not want to set neither

duration or start or end date, but let this be calculated
dynamic based on that the task should start and end in
relation to some other tasks. When I set the predecessors
of the the task, start-to-start and finish-to-finish, I do
get the timeframe the task should be within, but it does
not calculate the actual duration of the task. An example
of this would be for instance an quality assurance task,
starting when a mobilisation task start and ending with
the final delivery. Thanks in advance!

 

[Nilu Talreja]

Hi,

In Ms Project standard 2002 ,if you defined task for 2 days and
project start date is 28th October then task starts on project start
date i.e 28-10-03 and it finishes on 30-10-03.

But according to our calculation 2 days means task should start on
28-10-03(8:00 - 5:00 pm) and 29-10-03 (8:00 -5:00 pm).

As per Ms Project calculation it shows task duration for 3 days?

Anyone can help me on this???

Thanks in advance.

 

[Steve House]

The length of your working day in the project calendar and the hours per day
entered in the Tools Options Calendar page are not the same. Remember
Project tracks everything in minutes. Assuming it is set for the default 8
hours per day, when you say a task is 2 days duration, that gets converted
to 960 minutes for storage in the database. When the task is placed on the
Gantt chart timescale, its start is positioned at the first working minute
possible and it ends when 960 working time minutes have been consumed as
defined by the project calendar.

 

[Nilu Talreja]

Hi Steve,

Thank you my problem is solved.

Bye

The length of your working day in the project calendar and the hours per day
entered in the Tools Options Calendar page are not the same. Remember
Project tracks everything in minutes. Assuming it is set for the default 8
hours per day, when you say a task is 2 days duration, that gets converted
to 960 minutes for storage in the database. When the task is placed on the
Gantt chart timescale, its start is positioned at the first working minute
possible and it ends when 960 working time minutes have been consumed as
defined by the project calendar.