Having troubles assigning percentage of time for resources on a t.

[Laura]

I am trying to record that a resource will only spend 25% of her time on a
main task (there are 4 subtasks under the task). I have opened the summary
task information box and clicked on resources under the units, I have tried
to change 100% to 25%, I click ok to save the change, but each time I go back
to the summary task information box, the allocation is back at 100%. Can
someone tell me what am I doing wrong?

 

[DavidC]

A summary task is just that. It summarises the underlying tasks. Resources
are applied to the tasks (not the summary task) and it is there that you
allocate the %ge of effort a resource applies to the task. If the resource
is working on the 'summary task' then it must be as part of one of the
underlying tasks or as another task forming part of the summary running in
parallel with one or more of the other underlying tasks. Eg if the resource
is checking a report being written, then maybe a task showing "check report"
with a start start dependency on it and a duration the same as the task being
checked but assigning the resource to that activity in terms of the
percentage of effort the resource will apply to the task. The same effect is
achieved by assigning the same resource and percentage to the task being
checked.

Hope this helps
Regards

 

[Steve House [MVP]]

David correctly discsusses why you should never, ever, assign resources to
summary tasks. In addition to the reasons he cites, doing so can serious
distort the work and cost metrics. Frankly, I've never understood why
Project doesn't just lock out the resource fields for summary tasks
altogether and refuse even to accept an assignment entered there.

Adding to that, you also need to keep in mind what assignment percentages
really mean. If Mary is assigned to a task at 25%, it does NOT mean she's
spending 25% of her time on it. Instead, it means that her attention is
divided between that task and other duties and over the course of the time
period the task is taking in the schedule, she's only getting out 25% of the
work she would have if she had not been distracted. In other words, during
a task that started at 8am and ended 8 hours later at 5pm, she got done the
same amount of work she could have done between 8am and 10am had she worked
full speed on it. She still spent her entire 8 hour workday on the task but
what she got accomplished could have been done in 2 hours FTE.

 

[Laura]

Thanks - this is helpful. Maybe what I am trying to do is too simplistic. I
merely want to be able to record that a task has an expected completion of 10
days and that a resource will be assigned to spend 25% of her time doing the
task. If I put in 10 days duration for the task and then assign Mary to 25%,
the task duration becomes longer (to accomodate for the fact that Mary can
only spend 25% of her time on the task). This is great functionality, but
not what I need. Is there a way to get around this? Thanks

 

[JulieS]

Hi Laura,

If you create your 10 day duration task. Split the screen (Window>Split) to
show the Task Form at the bottom. In the Task Form, select Mary from the
drop down list and enter 10% in the units field. Click OK. Project will
calculate the work based upon the 10 day duration and Mary's assignment units
of 10%.

You are correct, if you initially assigned Mary at 100% and then dropped her
assignment units to 10% it will expand the duration, but if you initially
assign her at 10%, you should be all set.

Hope this helps. Let us know how you get along.

Julie

 

[DavidC]

One option (and possibly the best approach) is to untick the effort driven
box and leave the task type at Fixed Units. That way the task duration will
remain at 10 days, even though you assign a resource at only 25%.

 

[Laura]

I set the duration for a task to 10 days, split the screen to get the task
form, assigned resource A to the task, unchecked the effort driven box, kept
task typa at fixed units, and then assigned resource A's units at 25%. When
I clicked back into the Gantt chart, the task duration time had moved to 40
days. What did I do wrong?
Thanks!!

 

[JulieS]

Hi Laura,

Duration, Units and Work are mathematically related.

When you assigned the resource to the task, and did not specify units,
Project assigned the resource at 100% and calculated 80 hours of work using
the formula Duration * Units = Work. (Assuming a day = 8 hours.) When you
changed the units, the work (80 hrs.) remained the same and to keep the
mathematical relationship in balance, Project recalculated the Duration by
using the formula Work/Units = Duration. (80 hrs/.25 = 40 days) If you need
the duration to stick at 10 days, and want the work recalculated when you
drop units, change the task type to fixed duration. Project will
recalculate the work to 20 hours based upon the formula Duration*Units =
Work.

As I noted in an earlier post if you don't wish to have to change task type,
simply make the initial resource assignment at 25% using the Task Form at
the bottom.

Hope this helps. Let us know how you get along.

Julie

 

[Mike Glen]

Hi David,

Welcome to this Microsoft Project newsgroup

When you changed the Effort Driven and the Type settings, you must click OK
to put Project into that mode BEFORE changing the data. Rember that the
Effort Driven setting only applies after you have already assigned resources
and are going back to change them. Try again

You might like to have a look at my series on Microsoft Project in the
TechTrax ezine, particularly #11 - Task Types, at this site:
http://tinyurl.com/2xbhc or this:
http://pubs.logicalexpressions.com/Pub0009/LPMFrame.asp?CMD=ArticleSearch&AUTH=23
(Perhaps you'd care to rate the article before leaving the site,
Thanks.)

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
MS Project MVP

 

[DavidC]

Hi Mike,

Thanks, It goes without saying that it is necessary to click 'OK' when
finishing otherwise there is no way of having changes recognised. I have had
many occassions to change Task type after developing the programme and the
process seems to work fine as long as having changed the task type, the
resources are assigned and then the duration re-entered. It is a bit fiddly
to change after the fact but it can be done relatively easily.

Regards

DavidC

 

[Mike Glen]

I think you missed my point. If you're unaware, and if you change any
settings and then the data and then OK, project adjusts the data based on
the old settings. You need to change the settings and then OK. Then any
data changes you subsequently make will be based on the new settings.

Mike Glen
Project MVP