Managing sustainable operations in waste-to-energy supply chains using social group optimization

This study proposes an integrated optimisation framework for a waste-to-biodiesel supply chain, addressing the need for economically viable and sustainability-oriented biofuel systems. The model simultaneously considers multiple heterogeneous waste sources, production facilities, transportation, storage, and distribution decisions within a unified structure. As a key methodological contribution, the study applies Social Group Optimisation (SGO) to efficiently solve the resulting large-scale, constraint-intensive optimisation problem and demonstrates its suitability for complex biofuel supply chains. The objective is to minimise total operational cost while improving resource utilisation and supply chain efficiency. Numerical experiments and a practice-inspired case study show that the proposed framework achieves stable convergence and generates feasible, cost-effective solutions under realistic operating conditions. Sensitivity analysis identifies production and transportation costs as dominant drivers of system performance, providing actionable insights for managerial decision-making. Overall, the results confirm that the proposed SGO-based framework serves as a practical decision-support tool for planners and managers in waste-based biodiesel supply chains.