expanding duration

[Richard Veber]

I have a project with a 'Research' task.
The resource units are fixed, and the duration and
therefore work are variable, determined by the fixed
start date, and the finish to start constraint to the
next task.

How do I set up the research task so that it 'expands or
contracts' as the start date of the next task is changed?

 

[Mike Glen]

Hi Richard ,

Welcome to this Microsoft Project newsgroup

Please see FAQ Item: 19. Hammock Tasks.

FAQs, companion products and other useful Project information can be seen at
this web address: http://www.mvps.org/project/

Hope this helps - please let us know how you get on

Mike Glen
Project MVP

 

[John Beamish]

Let us call the "next" task "Publish"

1. Create the Research task.
2. Create the Publish task.
3. On the Publish task, click on the start date, click on Edit | copy
4. On the Research task, click on the finish date, click on Edit | Paste
Special ... | Paste Link and click on the OK button. You must click on the
"paste link" radio button.

From then on, whenever you adjust the Start date of the Publish task the
finish date of the Research task will change.

A couple of notes:
1. When you first perform step 4, the start date of "Research" will jump
backward. That's okay. Change the Start date of Publish and you will find
that everything will appear correctly.
2. You can do the same with the start date of Research and link it in the
same way to the finish date of an earlier task. This will create a Research
task where the start date depends on the finish date of a preceding task and
the finish date depends on the start date of a following task and the
duration will vary automatically.
3. You can also link the tasks so that the Gantt chart shows the linkage
between the two tasks.
4. Whenever you open the plan you will be asked if you want to update the
links. You should probably click yes.

JLB, PMP

 

[Steve House]

The Hammock task advice will work for this if you remove the FS link,
but are you sure it's the right approach? What determines the start
date of the successor task? You are saying it is a finish to start
"constraint" - I assume you mean "link" - but a FS link means the finish
of research determines the earliest date the successor can start, not
the other way around, so it must be something else that determines when
that successor starts. Let's say that research starts 01 Feb and
whatever determines the start of the successor task sets it to start 01
Mar. It sounds like you're saying that 01 Mar the research will end,
regardless of whether any progress has been made or not or what has been
learned from it. How can that be true in the real world? When you do
research, it usually continues until its objective have been achieved -
the problem from a PM viewpoint is estimating how long it might take to
reach the goal when it is an unknown.

Just something to think about.

 

[Jimmy]

Can you give me a real life example of when to use a
Hammock Task? Just looking to learn something new.

 

[Steve House]

Real life example - the project manager estimates that his job will take 4
hours per day for the duration of the project however long it lasts. If the
project gets longer his job gets longer. If it gets shorter, his job gets
shorter. His job doesn't determine the length of the project but instead is
determined by it. Create a hammock task "management" with the project start
milestone driving the start of the job and the project finish milestone
driving the end of the task. Use Copy, Paste Link for the management task
start and end dates, copying the dates that are to drive its length. Assign
the project manager to the task @ 50%.

Steve House
MS Project MVP

 

[Richard Veber]

Thanks to all who responded to my request, we are very
knowledgable about Hammock Tasks.
I also found a useful tip at this link, entitled Hammock
Tasks are fussy!
http://www.microsoft.com/mspress/books/sampchap/5590b.asp#1
12
I found that once you create a Hammock task, it is best to
have links at both ends if both start and end dates depend
on other task dates.