Completion attempts represent a single pass through crewmember's bid group. If a crewmember is awarded a block without the N-PBS Scheduler having to enter Denial Mode, it has performed one completion attempt. However, once the N-PBS Scheduler enters Denial Mode, a new completion attempt is started each time a bid preference is denied.

Every subsequent completion attempt clears all pairings from the Crewmember’s block which were awarded in the previous attempt and starts processing the bid again. Completion attempts are never seen by Administrators or Crewmembers, but are important in understanding how the N-PBS Scheduler manages Denial Mode.