This paper proposes a reduction method to verify the generalised soundness of large workflows described as workflow nets–a suited class of Petri nets. The proposed static analysis method is based on the application of six novel reduction transformations that transform a workflow net into a smaller one while preserving generalised soundness. The soundness of the method is proved. As practical contributions, this paper presents convincing experimental results obtained using a dedicated tool, developed to validate and demonstrate the effectiveness, efficiency and scalability of this method over a large set of industrial workflow nets.