Before revision:  With that results, we then study the optimum level of redundancy from the perspective of average job compute time and compute time predictability. We derive the efficient redundancy level as a function of tasks' service time distribution .
After revision:  With that results, we then study the optimum level of redundancy from the perspective of average job compute time compared to the overlapping schemes proposed in the literature. Furthermore, we derive the optimum redundancy level as a function of tasks' service time distribution .