CoupleEvo

An LLM heuristic-evolution method for problems made of several linked sub-problems, with three ways to coordinate the evolution.

Read the paper

The loop

  1. Proposes

    Heuristics for each sub-problem, written by an LLM inside an evolutionary loop

  2. Judged by

    Running the combined heuristics on instances of the coupled problem

  3. Steers

    Sequential, iterative or integrated schedules decide which sub-problem's heuristic evolves in each generation

Headline result

On two coupled problems (inventory routing, and multi-robot multi-bay pre-marshalling) with Qwen3-coder:30b, the sequential and iterative strategies converged more stably than the integrated one. On inventory routing the mean relative gap was 0.0429 (sequential), 0.0433 (iterative), 0.0537 (integrated).

What this does not prove

Two problems and one model. The paper's own text says iterative has the smallest median on one problem while its table shows sequential lower, so read the tables, not the prose. Accepted to a GECCO 2026 workshop.

How it generalizes the harness

An evolutionary schedule over several sub-heuristics is the solver, and the evolved heuristics run without the model.

Classification

Classification of CoupleEvo
What it proposesHeuristic
Generative modelQwen3-coder:30b, frozen
Algorithmic authorityEvaluation on coupled-problem instances
FeedbackScore
What gets updatedPopulation of candidates
When it runsOffline, at design time
ValidityEmpirical (measured)
EvidenceExperiments reported
LineageDerivative