Ordering Cost
Definition
The fixed cost incurred each time an order is placed, independent of order size, covering activities like purchase order processing, receiving, inspection, and invoice handling. In manufacturing, the equivalent is setup cost.
In Practice
Ordering cost is the per-transaction friction of replenishment: buyer time to create and expedite the PO, receiving and put-away labor, inspection, and accounts payable processing. In production settings the analogue is machine setup and changeover cost. Because it is fixed per order, spreading it over larger quantities lowers cost per unit, which is why it pulls lot sizes upward in the EOQ trade-off.
Estimating it well matters more than most teams assume. A common shortcut, dividing total purchasing department cost by orders placed per year, gives a workable starting figure. As e-procurement and EDI automate transactions, true ordering cost falls, which justifies smaller, more frequent orders and lower cycle stock.
Example: a buyer estimates 45 dollars per purchase order. After the company implements automated PO release and supplier portals, the cost drops to 12 dollars, and recalculated EOQs shrink order sizes by roughly 48 percent across the C-item portfolio.
Related Calculators
Related Terms
The cost of storing one unit of inventory for a defined period, commonly expressed in dollars per unit per year. It is the per-unit form of inventory carrying cost used in lot-sizing formulas.
Economic Order QuantityThe order size that minimizes the combined cost of ordering and holding inventory. EOQ balances the fixed cost of placing orders against the cost of carrying stock.
ReplenishmentThe process of restocking inventory to meet ongoing demand, whether by purchasing from suppliers, transferring between locations, or triggering production. It is the execution engine that keeps stock policies real.