One of the factors tha determines the performance of a computer is CPU scheduling. From the perspective of a computer user, minimal turn-around time is an important performance measure of a computer. The use of appropriate CPU scheduling algorithm can reduce turn-around time which in turn will improve the performace of a computer. Direct experiments on real operating system and computer impose much effort and difficulties. by using a simulation,CPU scheduling algorithms under workload condition can be studied and compared. Simulation experiments were executed first and yielded the smallest turn-arround time. Therefore shortest job first algorithm is the best scenario for system inprovement. Keywords: Simulation, Turn-Around Time, CPU Scheduling Algorithms