Table 4 Comparative summary of existing hybrid ANFIS-based models and the proposed GEP–ANFIS framework124,125,126.

From: Intelligent demand-side energy management via optimized ANFIS–gene expression programming in hybrid renewable–grid systems

Model

Optimization Strategy

Structural Adaptation

Learning Mechanism

Computational Complexity

Limitations

Distinct Contribution of Proposed GEP–ANFIS

ANFIS–GA

Genetic Algorithm for parameter tuning

Fixed fuzzy structure; only parameters optimized

Global stochastic search + ANFIS gradient fine-tuning

Moderate–High

Prone to local minima, slow convergence

Introduces symbolic rule evolution via GEP; enables both rule and parameter optimization

ANFIS–PSO

Particle Swarm Optimization

Fixed fuzzy structure

Particle-based swarm exploration + ANFIS adaptation

Moderate

Sensitive to initial conditions; lacks interpretability

GEP evolves interpretable rule expressions before ANFIS refinement; improved generalization

ANFIS–XGBoost

Gradient-boosted regression for feature optimization

No fuzzy structure adaptation; black-box ensemble

Gradient boosting with tree ensembles

High

High data requirement; poor explainability

Combines symbolic regression (GEP) with fuzzy reasoning (ANFIS) for transparent hybrid optimization

ANFIS–PSO–GA

Dual metaheuristic parameter tuning

Fuzzy structure static

Hybrid PSO–GA + ANFIS local learning

Very High

Computationally expensive; unstable for real-time use

Reduces computational cost via zero-order GEP optimization requiring fewer iterations

Proposed GEP–ANFIS

Gene Expression Programming for structure evolution + ANFIS hybrid learning

Dynamic rule evolution and adaptive membership functions

Symbolic regression (GEP) + local hybrid learning (ANFIS)

Low–Moderate

None observed; scalable with fewer samples

Dual-layer optimization (structural + parametric), interpretable rules, scalable to dynamic industrial EMS