Abstract: In recent years, with the rapid development of e-commerce, sorting orders are characterized by small batches, multiple varieties, short delivery cycles, and high precision requirements, which imposes higher requirements on sorting operations. For the sake of shortening sorting time, reducing sorting costs, and improving the sorting efficiency, logistics enterprises have gradually used double-layer sorting equipment. In this paper, the "component-sorting" is used to improve the utilization rate of pallets. "Component-sorting" refers to the method of sorting scattered single-piece packages according to certain rules and becoming a standardized large sorting unit. According to the definition of "component-sorting", the problem of destination assignment for a double-layer sorting equipment considering the component-sorting is studied and an efficient variable neighbor tabu search algorithm is designed that can solve the problem within a short time. The experimental results show that the efficiency of sorting equipment can be effectively improved by adopting the "component-sorting" and considering destination assignment problem.

Key words: double-layer sorting equipment, component-sorting, destination assignment problem, variable neighbor tabu search algorithm