Data Structure Design and Order-Picking Optimization for Irregular Warehouse

In order to calculate the distance between every two storage points, this paper proposed a data structure to store irregular warehouse layout diagram. A warehouse unit can be defined as four kinds, which are storage point, passage, node and block respectively. Storage point is a unit to store goods. Passage is an aisle by which the operator can access goods stored on storage point. Node is the intersection of a vertical passage and a horizontal passage. The number of nodes is evidently smaller than the number of storage points. So, we can compute out the shortest distance and route between every two nodes and save these data in disk. Then, when we need to calculate the shortest distance and route between two storage points, we can turn to these two storage points' adjacent nodes. Because of the limit of the order-picking vehicle's capacity, an order usually needs to be divided into several order-picking operations. In this paper, a hybrid genetic algorithm is proposed to optimizing order-picking. A chromosome consists of storage point's order in an order and the order-picking beginning point. A chromosome determines the number of order-picking operations and the total distance. The chromosomes evolve by special designed crossover and mutation operators. The experimental results revealed this new hybrid genetic algorithm's better performance^.