Abstract: For the scheduling problem of PDP (product design project), the stochastic effect of task duration and the possibility of rework are both taken into account to extend the conventional computational method of priority rules. A heuristic scheduling approach is therefore presented introducing the extended priority rules and the stochastic serial schedule generation scheme so as to form a schedule with the objective of minimizating the project makespan. The near-optimum scheduling strategy is obtained by means of sampling the stochastic task duration vectors. The proposed method was tested with different duration variabilities, and the results verified its effectiveness and revealed that the stochastic method for PDP scheduling is able to provide much higher quality of solutions in the case of duration uncertainty and rework possibility are higher.