Project assignment defaults to zero for task level resource planning

This was recently implemented at a project level but we constantly have the issue of adding a resource at the task level and the work time defaulting the to the full amount of that person's availability.  Ex: if a person is available 8 hours per day and the task is set at 2 days of duration once they are added as a resource it puts 16 hours of work time in as a default.

We add resources at the task level in back-up type situations where someone is out and a resource needs to step in and track time to certain tasks.

Thanks!