Supply chain glossary
Safety Stock
What safety stock is, what drives the right level, and the standard formula for sizing it.
30. july 2026
2 min
Safety stock is the inventory a company holds above expected demand to protect product availability against fluctuations in demand and supply. It works as a buffer: when actual sales exceed the forecast or a supplier delivers late, safety stock covers the gap instead of a stockout.
The right level of safety stock is a trade‑off. Too little causes stockouts and lost sales; too much ties up working capital and increases carrying costs. Three inputs drive the calculation:
- Target service level – the probability of not running out during a replenishment cycle (e.g. 98 %)
- Demand variability – how much actual demand deviates from the forecast
- Lead time and its variability – how long, and how reliably, suppliers deliver
A common formula: safety stock = z × σd × √L, where z is the service‑level factor, σd the standard deviation of demand and L the lead time in periods. In practice, retailers and manufacturers size safety stock per SKU and location, not with one blanket rule.
Safety stock in practice
Veritico STOCK sets safety stock dynamically per SKU and location from forecast error and target service levels, and recalculates it as demand patterns change. See demand forecasting and inventory optimization and replenishment and allocation management, or how Albert improved availability with fresher stock.
Related terms
More supply chain insights
Supply chain glossary
MAPE
What MAPE measures, the formula and a worked example, why it is undefined at zero demand and how minimising it biases forecasts downwards.
21. august 2026
4 min
Supply chain glossary
Forecast Accuracy
What forecast accuracy measures, the formulas behind it, and why the same forecast reports 90 % at one level of aggregation and 55 % at the level orders are placed.
21. august 2026
4 min
Supply chain glossary
Demand Planning
What demand planning is as a process, how it differs from demand forecasting, and how to tell whether manual adjustments to the forecast add value or subtract it.
20. august 2026
3 min