We generally operate our workbenchs with the "first in - first out" scheme. Occassionally, we will allow the use of a 'Rush' to interrupt this cycle. A travelling professional say, who needs some work accomplished while in town may request a rush. We don't really like doing this, so we reserve the right to say "No!", but generally we can accomodate. A rush pushes you to the top of the 'in-basket', and therefore pushes everyone else back a certain period of time.