Hello th,
When you change the duration of a task with resources assigned,
Project prompts you with two choices:
"Work required to do this task has increased so it will take longer"
or
"Resources will work fewer hours per day so it will take longer"
If you select the first option (the default) the amount of work on the
task will increase. For example:
If your task was originally 1 day duration with one resource assigned
at 100%, the amount of work for the resource on the task was 8 hours.
If you increase the task duration to 2 days and select the first
option, Project will increase the amount of work for the resource to
16 hours.
If you select the second option, the amount of work on the task will
stay the same and Project will decrease the assignment units for the
resource. For example:
If your task was originally 1 day duration with one resource assigned
at 100%, the amount of work for the resource on the task was 8 hours.
If you increase the task duration to 2 days and select the second
option, Project keep the amount of work at 8 hours and decrease the
resource's assignment units to 50%.
The selection you made from the options presented to you are not
stored by Project, just the results of your selection.
There is a mathematical relationship between task duration, resource
assignments, and work. It is usually depicted as Duration * Units =
Work. If you change one of the values (work, duration, or units)
Project must change one of the other variables to keep the
relationship true.
In my opinion, the best way to see what the values in the relationship
are is to view the Task Form at the bottom of the Gantt chart view.
From the Gantt chart view, choose Window > Split to display the Task
Form. In the Task Form you can see assignment units, duration, and
work. The "Task Type" options (Fixed Units, Fixed Work, Fixed
Duration) allow you to select which of the three values in the
mathematical relationship you wish Project to leave alone if you
change one of the other variables.
In a fixed unit task type:
if you change duration, Project changes work, leaving units the same.
if you change work, Project changes duration, leaving units the same.
In a fixed work task type:
if you change duration, Project changes units, leaving work the same.
if you change units, Project changes duration, leaving work the same.
In a fixed duration task type:
if you change units, Project changes work, leaving duration the same.
if you change work, Project changes units, leaving duration the same.
Help in MS Project does a good job explaining task type as well as
effort driven and non-effort driven.
I hope this helps. Let us know how you get along.
Julie
Project MVP
Visit
http://project.mvps.org/ for the FAQs and additional information
about Microsoft Project
