Optimal design of rack structure with modular cell in automated storage and retrieval systems

In this paper, the model of AS/RS with the rack of modular cells is proposed first. In general, under the concept of unit load, Automated Storage/Retrieval Systems (AS/RS) has the rack of equally sized cells. Many authors have studied the design of AS/RS with the rack of equally sized cells. However, they are inadequate and inefficient in meeting the various sizes of customers' demands in today's business environment. Higher utilization and flexibility of warehouse storage can be achieved by using AS/RS with the rack of modular cells. The best size of modular cell is determined as a decision variable and the effectiveness of the proposed model is also presented. The model developed in this research is one type of AS/RS that is more flexible to the size and has higher space utilization than those of existing rack structure, and could be a very useful alternative for the storage of different unit load sizes.