1. A method for scheduling a group of periodically recurring, non pre-emptible tasks on a server, wherein said group of tasks includes a first class of tasks having periods greater than or equal to computation times, said periods (hereafter designated P.sub.i) being representative of intervals at which tasks are to begin and said computation times (hereafter designated C.sub.i) being representative of run times for said tasks, and further wherein said server has a first sub-group of processors available for processing said first class of tasks, said method comprising the steps of: partitioning said first class of tasks into one or more disjoint sets; and determining scheduleability of said first class of tasks on said first sub-group of processors based on a function of computation times for said first class of tasks and a greatest common divisor of said periods for tasks in said first class of tasks, wherein said first class of tasks is scheduleable on said first sub-group of processors if each of said disjoint sets is determined to be scheduleable.