Retailers have long tried to balance the trade-offs between transportation and inventory costs by picking the correct delivery frequency. If you deliver to your stores every day, you can get away with minimal inventory investment, but transportation costs are high. If you deliver once a week, transportation costs are low, but you need a lot of inventory to avoid costly stock-outs.
Recently, more retailers are taking advantage of advances in transportation and inventory optimization to develop better strategies.
The same trade-off exists, but retailers are finding that they can do better by having different strategies for different stores or for different products.
For example, some stores may get daily deliveries while others receive shipments only twice a week. In addition, some products may take a different path to get the store rather than the normal delivery truck.