If you are looking in the Performance Intra-Day module, the variance is telling you the difference between the number of agents you actually had scheduled versus your optimal staffing. The optimal staffing is calculated by the system using the actual IV, AHT and service objectives that were defined when creating your forecast. If it is a negative number, than it means you were actually overstaffed and had more agents scheduled than what was optimally needed based on the actual load. It is kind of explained here: http://docs.genesys.com/Documentation/WM/8.1.3/Admin/AboutMon