Avoiding cross‐contamination in bulk logistics while minimizing costs and empty miles with novel decomposition‐based approach

Abstract We address a bulk logistics problem incorporating cross‐compatibility constraints, setting it apart from traditional vehicle routing problems. In bulk logistics, the interaction between orders must be carefully managed to prevent contamination risks, leading to new product‐sequencing constraints. Several vehicle routing literature's primary focus has been constraints such as location requirements and similar factors. However, our work introduces a novel approach by characterizing the cross‐contamination relationship for each order using a complex mathematical formulation. This approach ensures that any feasible and optimal route adheres to these compatibility relationships, with the aim of minimizing the risk of contamination. Our contributions are threefold. First, we establish a comprehensive mathematical model for bulk dispatch that explicitly incorporates order compatibility constraints. Second, we develop specialized graph decomposition‐based theories that are innovative and proven to be optimal in reducing cross‐contamination of orders in bulk transportation. Finally, we introduce a new metric called the incompatibility ratio and highlight the impact of the change in this metric on the empty miles. Together, these contributions provide a robust solution framework for managing order compatibility in bulk transportation and provide solutions in a fraction of a second compared to the comprehensive model, addressing the theoretical and practical challenges inherent in this complex logistics problem.