Abstract : In this paper, we address for safety critical ap- plications the problem of multiprocessor real-time scheduling while taking into account the exact preemption cost. In the framework of multiprocessor real-time partitioned scheduling, we propose a greedy heuristic which balances the load of the tasks on all the processors and minimizes the response time of the applications. That heuristic uses a schedulability condition which is based on the ⊕ operation. That operation performs a schedulability analysis while taking into account the exact preemption cost. A performance analysis is achieved which compares the proposed heuristic to the branch and bound exact algorithm and to the worst-fit and best-fit heuristics.