I have a resource that was initially going to be assigned 100%. I want to change the resource availability to 50% and have that change effect all tasks current assigned. It doesn't seem to be doing that. The task is retaining the 100% allocation.
Changing maximum units after assigning resources does not change assignment units. You may use the "replace" command in the Assign resource dialog to replace the resource with the same resource and manually enter the lower assignment unit. Assuming the tasks are not fixed duration, the duration of the tasks will increase.
Setting a resource's 'Max Units' value will not prevent you from over allocating that resource, and it will not change any of that resource's existing assignments as Julie stated. Unfortunately, you will need to find all of that resource's assignments in the project schedule and change the assignment units for each.
Fortunately, there is a relatively easy way to accomplish this:
- Open the project schedule with Microsoft Project.
- Apply the 'Resource Usage' view: 'View' ribbon tab > 'Resource Usage' command
- Insert the 'Assignment Units' column into the left table portion of the view: 'Format' ribbon tab > 'Insert Column' command > Select 'Assignment Units' field.
- Locate the desired resource in the left table portion of the view; their assignments should be listed below their name.
- Change the 'Assignment Units' value next to each of the resource's assignments.