Aggregation permits a supply chain to reduce the replenishment lot size of individual products while still achieving economies in ordering and transportation. If every product is ordered independently, each SKU must absorb the fixed cost associated with placing and moving that order. This creates an economic incentive to order relatively large quantities so that the fixed cost is distributed across more units.

When several products, retailers, or suppliers are aggregated into a common order or shipment, the fixed replenishment expense is shared. The effective fixed cost assigned to each product therefore decreases. Because economic lot size is positively related to fixed ordering cost, lowering the effective fixed cost makes smaller replenishment quantities economically attractive.

Option D is therefore correct. Aggregation does not itself increase customer demand, nor does it necessarily reduce the holding-cost rate per unit. Instead, it reduces average inventory by permitting smaller individual lots. The reduction in inventory subsequently lowers total holding expenditure.

The managerial objective is important: maintain transportation or ordering economies at the consolidated level while reducing cycle inventory at the individual-product level. This supports lower working capital, faster inventory turnover, and more responsive replenishment.

Reference Topic: Inventory and Warehousing — Cycle Inventory and Aggregated Replenishment.

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