It depends, if someone with less seniority than you has already taken/passed the sort test then they can skip you by using "present qualified and available." If no one has taken/passed the sort test they really should be putting up a bid sheet and going by seniority, but the inside bid sheets are more often ignored by both hourly and management, so if you want to move to the sort express the interest and take the test. If there's no openings and you pass the test well as soon as one opens you're in if someone isn't over you in seniority. If you're sort qualified and they put someone with less seniority on the sort aisle ahead of you find out if they put out a bid sheet for it, if they did and the person didn't sign it or they didn't grieve it. If there was a bid sheet and the other person signed it and you didn't you won't win a grievance and will have to wait longer.