Variables
Description
What is this formula?
The Reorder Point (ROP) determines the inventory level at which a new order should be placed to avoid stockouts during supplier lead time.
It combines expected demand during lead time with an additional safety stock buffer.
When to use it
Use this formula when:
- Managing inventory replenishment.
- Preventing stock shortages.
- Planning purchase orders.
- Improving service levels.
- Optimizing warehouse operations.
Example
A company sells:
d = 50 units/day
Supplier lead time:
L = 8 days
Safety stock:
SS = 100 units
Formula:
ROP = dL + SS
Substitution:
ROP = (50×8) + 100
ROP = 500 units
Result:
A new order should be placed when inventory reaches 500 units.
Applications
- Inventory management
- Supply chain planning
- Purchasing operations
- Warehouse management
- Service level control
Note
This model assumes average demand and lead time values. In practice, demand variability and supplier uncertainty are often incorporated through the safety stock term to achieve a desired service level.