Digital Twin and Constraint-Guided Generative Decision Support for Human-Machine Collaborative Manufacturing under Industry 5.0

INTRODUCTION: In Industry 5.0 manufacturing systems, adaptive decision support is required to handle demand fluctuations, machine degradation, and operational feasibility constraints under human supervision. However, existing digital twin and data-driven approaches remain primarily focused on monitoring or forecasting, with limited integration into decision-oriented production control and feedback adaptation. OBJECTIVES: This study aims to develop a human-in-the-loop adaptive production decision-support framework that transforms external demand signals into feasible, risk-aware, and reviewable production actions by integrating demand-production state fusion, digital twin-based constraints, structured generative decision decoding, and feedback-driven updates. METHODS: A constrained decision-making system is constructed using Online Retail II and AI4I 2020 datasets. A unified state representation is learned by fusing demand indicators with manufacturing digital twin variables. A constraint-guided policy decoder is designed to generate discrete production actions under feasibility constraints rather than performing demand forecasting. Human feedback is encoded into subsequent decision states to enable iterative adaptation. The model is trained via a unified optimization objective balancing demand alignment, risk control, and explanation consistency. RESULTS: Experimental results on two datasets show that the proposed framework achieves improved demand-production alignment while consistently reducing manufacturing risk exposure and human override rates compared with forecasting-based and decision-oriented baselines. CONCLUSION: The proposed framework demonstrates that integrating digital twin constraints, constrained generative decision-making, and human feedback enables a shift from demand prediction to feasibility-aware production decision optimization, improving safety, interpretability, and human acceptability in Industry 5.0 manufacturing systems.