Duration changes with multiple resources

[Doug]

I have a project whose tasks total 600 hours. Of the 600 hours there are
tasks and sub-tasks. If I add multiple resources (let's say 3 resources) for
each task, the duration for each task shows 1/3 of the time of the total
task. (i.e. a task estimated at 30 hours will show a duration of 10 hours
after adding 3 resources at 100%). Project will also pull in the finish dates
reflecting 10 hours of work instead of 30 (which is fine).

How can I get Project to continue to reflect the actual total number of
hours of effort (in this case 600) with multiple resources performing each
task? My objective is to show that the project requires 600 hours of effort,
but will not require 600 consecutive hours for completion.

Thanks.

 

[John]

I have a project whose tasks total 600 hours. Of the 600 hours there are
tasks and sub-tasks. If I add multiple resources (let's say 3 resources) for
each task, the duration for each task shows 1/3 of the time of the total
task. (i.e. a task estimated at 30 hours will show a duration of 10 hours
after adding 3 resources at 100%). Project will also pull in the finish dates
reflecting 10 hours of work instead of 30 (which is fine).

How can I get Project to continue to reflect the actual total number of
hours of effort (in this case 600) with multiple resources performing each
task? My objective is to show that the project requires 600 hours of effort,
but will not require 600 consecutive hours for completion.

Thanks.

Doug,
I believe you are getting Duration hours confused with Work hours.
Duration is the time span during which effort is expended on the task.
Work is the amount of effort to perform the task. Adding or removing
resources to/from a task will change the Duration time but it will not
change the work content. I think all you need to do is to display the
Work field. You should then see the 600 hours on the top level Summary
line.

Hope this helps.
John

 

[Doug]

John,

Thanks - I think you're right. One other question - When I display the work
column next to the duration column and enter the same number of hours for
each task/sub-task, the totals differ by a few hours (duration is a little
higher). This is before I enter any resources. Do you know why that would be?

Thanks.

Doug

 

[John]

John,

Thanks - I think you're right. One other question - When I display the work
column next to the duration column and enter the same number of hours for
each task/sub-task, the totals differ by a few hours (duration is a little
higher). This is before I enter any resources. Do you know why that would be?

Thanks.

Doug

Doug,
At first I didn't understand what you were asking but then the bulb went
on. I was also confused when you said you were entering values for
tasks/sub-tasks. In the normal definition the actual effort description
is a sub-task under a Summary Line and Summary lines are not tasks, they
are simply a summary of the sub-task information indentured under them.
So in effect, neither Duration nor Work can be "entered" for Summary
Lines, those values are calculated by Project.

Now to answer the question. The Work on a Summary Line is the arithmetic
sum of the Work for each sub-task under the summary. However, the
Duration value shown on a Summary line is the difference in time between
the Start of the earliest task (i.e. sub-task) and the Finish of the
latest task under the Summary Line. Therefore depending on how the
sub-tasks are linked (default is finish-to-start), the Summary Line
Duration value can be less than, equal to, or greater than the Summary
Line Work value.

Hope this helps.
John

 

[Steve House [Project MVP]]

Duration on a summary task that has several subtasks under it is the length
of time from when the earliest subtask starts until the lastest subtask
finishes - it is the the simple arithmentic sum of the subtask durations. I
have a task with 2 1-day subtasks. Those two tasks are linked so thet occur
one after the other. Each subtask is 1 day and the summary is 2 days. But
if I add a 2 week lag time between the two subtasks so there is a delay
between when the first one ends and the second one starts, the sum of their
durations is still 2 days but the duration of the summary task becomes 12
days.