Dynamic flexible flow shop scheduling via cross-attention networks and multi-agent reinforcement learning

Abstract

With the increasing uncertainty in production environments and changes in market demand, flexible and efficient scheduling solutions have become particularly critical. However, existing research mainly focuses on static scheduling or relatively simple dynamic scheduling problems, which are inadequate to address the complexities of actual production processes. This paper considers the dynamic flexible flow shop scheduling problem (DFFSP) characterized by diverse processes, complexity, and high flexibility, and proposes a multi-agent reinforcement learning algorithm based on cross-attention networks (MARL_CA). First, this paper proposes a novel state feature representation method, which represents the job processing data and the production Gantt chart as a state matrix, fully reflecting the environment state in the scheduling process. In addition, a cross-attention network is proposed to extract state features, enabling efficient discovery of complex relationships between jobs and machines, thereby enhancing the model's ability to understand intricate features. The model is trained using an independent proximal policy optimization (IPPO) based on the actor-critic method to help agents learn accurate and efficient scheduling strategies. Experimental results on a large number of static and dynamic scheduling instances demonstrate that the proposed algorithm outperforms traditional heuristic rules and other advanced algorithms, exhibiting strong learning efficiency and generalization capability.