Publication Type
Conference Proceeding Article
Version
acceptedVersion
Publication Date
12-2026
Abstract
Traditional neural solvers for solving vehicle routing problems (VRPs) often suffer from limited solution diversity, motivating the development of Generative Flow Network (GFlowNet)–based models. However, the effectiveness of these models is frequently constrained by insufficient flow expansion in high-reward regions, limiting their ability to distribute probability across promising solution routes. The deeper exploration could yield superior results. Diffusion models, in contrast, provide stronger structural guidance for exploration. These two paradigms are naturally complementary: GFlowNet can supply edge-level signals for diffusion to embed, while diffusion can guide broader exploration. Leveraging this synergy, we propose Diffusion-Enhanced GFlowNet (DEG), a novel framework that integrates GFlowNet with a diffusion model to encourage richer flow expansion toward highreward regions and derive higher-quality solutions. Specifically, DEG exploits GFlowNet’s inherent diversity to generate edge-specific backward signals, applies the stochastic noise schedule of diffusion to perturb these signals, and then denoises them within the GFlowNet paradigm. To further improve scalability, we introduce a specialized decoder capable of dynamically adapting to diverse problem scales. Extensive experimental evaluations on synthetic and real-world datasets, including instances with up to 10,000 nodes, demonstrate that DEG consistently achieves favorable performance compared to baseline methods. The code is available at https://github.com/ZHANG-NI/DEG.
Keywords
Vehicle Routing Problem, GFlowNet, diffusion
Discipline
Artificial Intelligence and Robotics | Operations Research, Systems Engineering and Industrial Engineering
Research Areas
Information Systems and Management
Areas of Excellence
Digital transformation
Publication
Proceedings of the Fortieth Annual Conference on Neural Information Processing Systems (NeurIPS 2026), Sydney, Australia, December 6-12
First Page
1
Last Page
22
City or Country
Sydney, Australia
Citation
ZHANG, Ni; ZHANG, Zhiqin; PAN, Ling; LAU, Hoong Chuin; and CAO, Zhiguang.
Diffusion-enhanced GFlowNet for solving vehicle routing problems. (2026). Proceedings of the Fortieth Annual Conference on Neural Information Processing Systems (NeurIPS 2026), Sydney, Australia, December 6-12. 1-22.
Available at: https://ink.library.smu.edu.sg/sis_research/11410
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Additional URL
https://neurips.cc/virtual/2026/loc/sydney/poster/155420
Included in
Artificial Intelligence and Robotics Commons, Operations Research, Systems Engineering and Industrial Engineering Commons