1. A computer-implemented method of predicting a staffing level for a call center system, the method comprising: enabling a user to input into a computer model through a graphical user interface a first call volume for a first time period, the first time period including a series of component time periods; electronically accessing an operational performance goal for the call center system and a first average handle time for the first time period; electronically accessing a staffing level distribution for the first time period, the staffing level distribution for the first time period including a staffing level value assigned to each component time period of the series of component time periods within the first time period; and determining within the computer model a first staffing level for the first time period based on the operational performance goal, the first call volume, the first average handle time, and the staffing level distribution for the first time period, and