A method, system and software for determining a final staffing schedule in a ticketing system by scheduling a plurality of staffing resource units (SRUs) of multiple classes into one or more shift(s). The method includes finding a simulated staffing schedule for some sub-set of class(es), where the sub-set of class(es) is: (i) less than the total number of classes; and (ii) can accomplish all tasks that may come in during the shift(s) being scheduled. The schedule for the sub-set of classes is then converted into a schedule including SRUs of every class based on historical data relating to historical proportions between SRUs of various classes and/or incoming tasks of various types.