Bestellpunktverfahren

What is the reorder point method?

The reorder point method is an inventory management approach in which a replenishment order is triggered whenever the available stock — meaning on-hand inventory plus open purchase orders — falls below a defined threshold known as the reorder point. The order quantity is typically fixed or calculated based on a lot size. The method belongs to the category of consumption-based planning and operates reactively: it responds to actual stock withdrawals rather than planned requirements.

The reorder point itself is derived from the average consumption during the replenishment lead time plus a safety stock. The safety stock buffers fluctuations in both consumption and delivery time. The appropriate level depends on the desired service level and the variability of demand and lead time — there is no universal formula, but well-established statistical approaches do exist.

How does the method work in practice?

In a warehouse management or ERP system, a reorder point is stored for each item. Every time goods are withdrawn or a posting is made, the system checks whether the current stock has fallen below this value. If so, a purchase requisition is automatically generated or — depending on configuration — an order is placed directly. The planner then simply needs to approve or adjust this proposal.

Typical use cases include C-items and consumables, spare parts with stable usage patterns, and traded goods with predictable demand. The method is less suitable for seasonal items or those with highly variable demand, as it relies on historical consumption figures and does not anticipate short-term changes in demand.

What matters when setting it up?

The quality of the master data on which the reorder point is based is critical:

• Average daily consumption: If set too low, stock-outs will occur; if too high, inventory will grow unnecessarily.
• Replenishment lead time: This should be regularly reconciled against actual delivery times, as supplier changes or supply chain disruptions can shift it.
• Safety stock: A buffer set too generously ties up capital and storage space; one set too low leads to supply interruptions.
• Order quantity: This influences how frequently and in what lot sizes orders are placed, and therefore affects holding costs, ordering costs, and capital commitment.

In practice, reorder points are often configured once and then never adjusted. This is a common mistake: if consumption behaviour or the supply situation changes, the parameters become outdated. Regular review — ideally supported by the ERP system — is therefore important, even though no defined standard prescribes how often this must occur.