I'm confused how this is different than the pbs system we have? I put on sheet one what I want..if it cannot build be what I want it goes to my second sheet. I bid a different way...try another angle. No luck...cool. Go to my third sheet. If you don't want to do it this way....bid reserve to get the days off you need. After all that...u didint get what you need...ok...trade, drop, swap...whatever...all in opentime and all same day...and sometimes instant. What's the big deal?