I once went on a course at Warwick Business School where one of the modules was a Call Centre simulation.  We had 4 levers that we could pull to keep call volumes within a given range, as over time the call rates fluctuated for various reasons.  Those levers were things like Overtime, Time Off, Praise / Bonuses and Coaching 9sonething like that).  As we moved the levers up and down we were supposed to analysis the impact. Over the simulation we moved the levers up and down as a group, somet