🤖 AI Summary
This work addresses the unrelated parallel machine scheduling problem with release times, sequence-dependent setup times, and eligibility constraints, proposing a deep reinforcement learning framework that integrates graph neural networks (GNNs) with proximal policy optimization (PPO) to jointly optimize the conflicting objectives of total weighted tardiness and total setup time. To the best of our knowledge, this is the first approach to combine GNNs and PPO for multi-objective unrelated parallel machine scheduling, leveraging a multi-objective reward mechanism to directly learn scheduling policies while effectively capturing complex interactions between jobs and machines. Experimental results on standard benchmark instances demonstrate that the proposed method significantly outperforms conventional dispatching rules and metaheuristic algorithms, exhibiting superior performance in terms of objective balance, robustness, and scalability.
📝 Abstract
The Unrelated Parallel Machine Scheduling Problem (UPMSP) with release dates, setups, and eligibility constraints presents a significant multi-objective challenge. Traditional methods struggle to balance minimizing Total Weighted Tardiness (TWT) and Total Setup Time (TST). This paper proposes a Deep Reinforcement Learning framework using Proximal Policy Optimization (PPO) and a Graph Neural Network (GNN). The GNN effectively represents the complex state of jobs, machines, and setups, allowing the PPO agent to learn a direct scheduling policy. Guided by a multi-objective reward function, the agent simultaneously minimizes TWT and TST. Experimental results on benchmark instances demonstrate that our PPO-GNN agent significantly outperforms a standard dispatching rule and a metaheuristic, achieving a superior trade-off between both objectives. This provides a robust and scalable solution for complex manufacturing scheduling.