In continuous review inventory model, (Q ,r ) system, order quantity(Q) and reorder point() should be determined to calculate inventory-related cost that consists of setup, holding, and penalty costs. The procedure to obtain the exact value of Q and r is complex. In this paper, a regression analysis is proposed to get the approximate inventory-related cost without the determination of and in the case that the standard deviation(σ) of the lead time demand is small or that the mean(μ) of the lead time demand is proportional to σ. To save inventory-related cost, central warehouses with (Q, r ) system can be built. Central warehouse can provide some stores with products with the consideration of the tradeoff between inventory-related cost and transportation cost. The number and the location of central warehouses to cover all the stores are determined by a regression-based approach. The performance of the proposed approach is tested by using some computational experiments.