Local Return Routing Strategy in a Flow-Picking System

As the blossom of e-commerce in the recent years, warehouse operation faces the challenges of small orders, large assortment, tight delivery schedules and varying workloads. Some advanced operation strategies are proposed to tackle these challenges during the order fulfillment in e-commence warehouse in practice. The flow-picking is a typical example, which has been successfully applied in several Chinese online retailers’ warehouses by its outstanding performance. In this paper, a new routing strategy with local return area is proposed based on the prototype of flow-picking system. Simulation experiments are conducted to obtain several valuable findings: 1) local return strategy can improve the system performance by reducing the average throughout time of orders in most scenarios; 2) local return strategy with different storage assignment policies has different impact on system performance. Among the three mentioned storage policies, full-turnover storage policy performs best; 3) the size of return area has important influence on the system performance. Too big or too small may lead to unsatisfactory results.