In this thesis, a parallelized real-time scheduling algorithm is simulated. The tasks are characterized by their processing time, deadlines, and resource requirements. Starting with an empty partial schedule, each step of the search extends the current partial schedule with one of the tasks yet to be scheduled. The heuristic functions used in the algorithm search for feasible schedule. It is investigated the performance of various heuristic algorithms by simulation. ZHAO's preemptive scheduling algorithm is modified to improve performance(Success Ratio). With original ZHAO's scheduling algorithm, two scheduling algorithms are compared via simulation. It is also investigated the running time of a parallized scheduling algorithm.