Glossary · business
Safety Stock
Extra stock held against demand and lead-time uncertainty — protects against stockouts during unexpected swings.
Buffer Stock
Safety stock is the buffer held above the average demand and average lead time. The point: don't run out when demand spikes or the supplier slips. Its size depends on three things: demand variability, lead-time variability, and the target service level. A high service level (e.g. 99%) means a large safety stock — more cash tied up. A low service level (e.g. 85%) means a small safety stock but more frequent stockouts. The decision is a trade-off.
Örnek
An SKU with mean daily demand 20 units, standard deviation 8, lead time 7 days. For a 95% service level: safety stock ≈ 1.65 × 8 × √7 ≈ 35 units.