In this paper, a new schedule generation scheme for resource-constrained project scheduling problems is proposed. Given a project scheduling problem and a priority rule, a schedule generation scheme determines a single feasible solution by inserting one by one each activity, according to their priority, inside a partial schedule. The paper proposes a generation scheme that differs from the classic ones in the fact that it allows to consider the activities in any order, whether their predecessors have already been scheduled or not. Moreover, activity insertion is performed so that delaying some already scheduled activities is allowed. The paper shows that this strategy remains polynomial and often gives better results than more classic ones. Moreover, it is also interesting in the fact that some priority rules, which are quite poor when used with classic schedule generation schemes, become very competitive with the proposed schedule generation scheme.