Intralogistics synchronization in robotic forward-reserve warehouses for e-commerce last-mile delivery.

• A novel delivery-driven intralogistics synchronization problem is proposed. • The model seeks a tradeoff between manual picking and robotic sorting operations with given delivery requirements. • The proposed synchronized solutions are consistently superior to the sequential solutions under various scenarios. This paper treats intralogistics processing in a typical robotic forward-reserve e-commerce warehouse involving a reserve area with manual order-picking operations and a forward area with robotic parts-to-picker order sorting operations. It is critical to synchronize intralogistics operations between the two areas considering delivery requirements to optimize the performance in terms of makespan and costs. This challenge is formulated as a delivery-driven intralogistics synchronization (DDIS) problem. This paper develops a tailored variable neighborhood search solution method. A series of comprehensive numerical experiments under various scenarios show the superiority and stability of the DDIS as benchmarked with sequential approaches. A substantial reduction can be achieved in both makespan and forward area size, indicating significantly improved intralogistics operational efficiency and space utilization. Managerial insights are also discussed for specific action plans regarding the market size, the labor force, and the trolley configuration. [ABSTRACT FROM AUTHOR]