HMACE: Heterogeneous Multi-Agent Collaborative Evolution for Combinatorial Optimization
Summary
HMACE, a Heterogeneous Multi-Agent Collaborative Evolution framework, is introduced as a novel approach to automated heuristic design for NP-hard combinatorial optimization problems (COPs). This framework reconceptualizes heuristic search as an organizational design problem, decomposing each evolutionary generation into a specialized loop with four coordinated agents: a Proposer for strategy exploration, a Generator for executable heuristic synthesis, an Evaluator for empirical assessment, and a Reflector for archive-backed memory updates. HMACE integrates behavior-aware retrieval, lightweight candidate filtering, and fitness-grounded archive updates to guide the search towards diverse and promising heuristic behaviors while minimizing redundant evaluations. Extensive evaluations on COPs like TSP, Online BPP, MKP, and PFSP demonstrate that HMACE achieves a favorable quality-efficiency trade-off, outperforming state-of-the-art single-agent and multi-agent baselines. Notably, it achieves the lowest average gaps on TSP (0.464%) and Online BPP (0.223%) with significantly fewer tokens (0.13M and 0.42M, respectively) compared to other LLM-driven methods.
Key takeaway
For Machine Learning Engineers developing LLM-based solvers for NP-hard combinatorial optimization problems, HMACE offers a blueprint for improving both solution quality and token efficiency. You should consider adopting a heterogeneous multi-agent architecture with explicit role specialization and an archive-backed memory. This approach can help your systems escape local optima and achieve more robust, diversified exploration, significantly reducing API costs and search time compared to monolithic or homogeneous multi-agent designs.
Key insights
Heterogeneous multi-agent collaboration with specialized roles and memory-guided reflection enhances heuristic discovery for COPs.
Principles
- Decompose complex search into specialized agent roles.
- Ground search in measurable performance, not self-reported quality.
- Use behavior-aware memory for diverse exploration and exploitation.
Method
HMACE employs a four-agent evolutionary loop: Proposer drafts strategies, Generator synthesizes code, Evaluator assesses performance and behavior, and Reflector updates an archive for memory-guided retrieval and search redirection.
In practice
- Implement lightweight filtering to conserve evaluation budget.
- Track both fitness and behavioral metrics for heuristics.
- Utilize a CVT-MAP-Elites archive for diversity-aware memory.
Topics
- Heterogeneous Multi-Agent Systems
- Combinatorial Optimization
- LLM-based Heuristic Design
- Evolutionary Algorithms
- Archive-backed Memory
Best for: AI Scientist, Research Scientist, Machine Learning Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by cs.AI updates on arXiv.org.