Dynamic Job Shop Scheduling via Deep Reinforcement Learning

Recently, deep reinforcement learning (DRL) is shown to be promising in learning dispatching rules end-to-end for complex scheduling problems. However, most research is limited to deterministic problems. In this paper, we focus on the dynamic job-shop scheduling problem (DJSP), which is a complex dynamic optimization problem under uncertainty. We propose a DRL based method to learn dispatching policies for DJSP. Unlike existing DRL based dynamic scheduling methods that use a fixed number of dispatching rules as actions, our decision-making framework directly selects legitimate jobs, which is able to break the limitations imposed by priority dispatching rules. We design two training methods, including a gradient based algorithm with dense rewards, and an evolutionary strategy with sparse rewards. Extensive experiments show that our DRL method can learn high-quality DJSP dispatching policies, and can significantly outperform a state-of-the-art Genetic Programming (GP) based dispatching rule learning method.