How do you implement a seniority system? Would people call in and "bid" on seats and then have them awarded? Or whomever calls in during that time frame gets the seat until someone senior calls above them?

Then the guy that gets booted no longer has a seat and now has to fight for FCFS (he could be senior just not senior enough!)? Or they book multiple jump seats in anticipation of getting kicked off a few?

Just seems like a problem in search of a solution.