Layout Design of Multiple Blocks Class-Based Storage Strategy Warehouses

Manual order-picking warehouses are highly influenced by its’ layout design. In fact, layout parameters play the most important role in determining the route length which is responsible for the largest share in a warehouse operating costs. Conventional simulation techniques are not capable to capture the complexities in dynamic systems. Therefore, this paper develops an agent-based model to simultaneously investigate the effects of order size in parallel with different layout parameters such as number of cross aisles, aisle length and number of aisles on the order-picking distance. Statistical analysis is performed on the results to specify which decision factors are critical to be considered in layout design. Sensitivity analysis is conducted among different layout configurations to determine which conditions give the maximum savings in route length. The results show that with class-based storage policy, adding an extra cross aisle to the one-block layout warehouse would result in a decrease in route length. However, having too many cross aisles could turn the balance. It also was found that the order-picking density is a significant factor that could lead to changes in layout preferences. The novel aspect of this research is the utilization of agentbased simulation in designing manual order-picking warehouses.