The short answer: safety stock is the extra buffer of inventory you hold to avoid running out when demand is higher than expected or a delivery is late. The right amount balances the cost of a stockout (lost sales, unhappy customers) against the cost of holding extra stock (tied-up cash).
Why you need a buffer
Demand and delivery times aren’t perfectly predictable. A busy weekend or a delayed supplier can empty a shelf before your next order arrives. Safety stock absorbs that variability so a normal surprise doesn’t become a lost sale.
How much to keep
There’s no single number — it depends on three things:
- How variable demand is — steady sellers need less buffer than erratic ones.
- How long and reliable your lead time is — longer or less reliable supply needs more.
- How costly a stockout is — protect your hero products more than easily-substituted ones.
A practical approach: give best-sellers and long-lead items a healthy buffer, keep it lean on slow, easily-restocked items, and adjust as you see real patterns.
Safety stock and reorder points
Safety stock is built into your reorder point: reorder point = (average daily sales × lead time) + safety stock. The buffer is the part that keeps you covered while a late order catches up.
The cost of getting it wrong
- Too little — stockouts, lost sales, customers who go elsewhere.
- Too much — cash frozen on shelves, higher dead-stock risk.
Set buffers intelligently
RushFlow lets you set reorder points with safety stock per product and alerts you before you run low — so you protect sales without over-investing in stock. See the live demo.