Durations not changing when I add resources

Josheddo

Well, the duration does change, for the electrician resource. Take a look at the Task Usage view in this emulation of your highlighted task.

Now add two more electricians to the task. Note the duration for the electrician resource is reduced.

This issue is that you did not make any changes for the apprentice resource so that resource is still assigned over the full original duration which means the task still has a duration of 11.6 days. Project cannot make the autonomous decision to also reduce the apprentice assignment because "it" has no knowledge that an apprentice only works when a journeyman works, it's not the sophisticated.

If you want the duration for the task to be reduced, you will also need to adjust the apprentice resource.

Hope this helps.
John