Inventory Replenishment: When to Reorder and How Much

Inventory replenishment decides when to raise a supply action and how much to request. Use the item’s demand, usable stock, relevant open supply, lead time and review frequency to choose a policy, then track the receipt through acceptance.

A reorder trigger and an order quantity answer different questions. Reaching the trigger means action is due; the supplier pack size, target stock and existing supply still affect how much to order.

Use a reorder point with continuous review

Illustrative assumptions: stable consumption of 20 units per day, five days from ordering to usable receipt, and a chosen 30-unit buffer. Reorder point = lead-time demand + buffer = 20 × 5 + 30 = 130 units.

Review the inventory position against that trigger: usable stock plus relevant open supply, less outstanding commitments not already reflected in your demand or available-stock figures. Document the convention so the same demand is not subtracted twice. The trigger alone does not specify a fixed order quantity.

Cover the extra interval in a weekly review

If buying is reviewed every seven days, supply may need to cover the review interval as well as the five-day lead time. Under the same stable-demand assumptions, the target position is 20 × (7 + 5) + 30 = 270 units.

The 90-unit position must be calculated using the same item, location and demand basis as the target. Late open orders may not cover the earlier shortage. Do not add an expected receipt merely because it exists in the system; check its quantity, date and other commitments.

Apply supplier and factory constraints

A 180-unit requirement may need adjustment for a minimum order or pack multiple. Record the resulting excess and why it was accepted. Check shelf life, storage, inspection workload, price breaks and the consequence of a late delivery before changing the order.

The 30-unit buffer is an assumption, not a guarantee against variable demand or lead time. Review actual usage, shortages and supplier performance over complete replenishment cycles. Order-specific parts may be better driven by the approved BOM requirement than by an average daily rate.

Create and follow the material action in Optiwise

Optiwise inventory supports min/max levels and automatic reorder indents. Smart Suggest checks BOM demand against stock, open purchase orders and existing production, then creates the basis for buying, in-house work or subcontracting. Purchasing follows the selected action through vendor commitment, GRN and quality acceptance.

Odoo's inventory overview provides a primary reference for min/max replenishment as a general inventory mechanism. Use our availability check to separate usable stock from holds, and the purchase workflow to assign the next handoff.

Questions from manufacturing teams

Is the reorder point the quantity to buy?

No. It is the trigger for action. Determine the order quantity using the chosen policy, inventory position and supplier constraints.

Why does weekly review need a larger coverage period?

The next opportunity to review and place an order is later. The example covers that review interval plus supply lead time.

Should I ignore open purchase orders?

No. Include relevant supply using consistent dates and allocation rules, while keeping late or restricted supply distinguishable.

Review one replenishment policy in Optiwise with your stock position, open orders and actual supplier lead time.