1
Understanding Safety Stock
Safety stock is extra inventory kept beyond expected demand to protect against uncertainty. It acts as a buffer against demand fluctuations, supplier delays, and forecast errors.
2
Calculating Safety Stock
The standard formula considers average daily sales, maximum daily sales, lead time, and maximum lead time. More sophisticated approaches use statistical methods based on desired service levels.
3
When to Adjust
Safety stock levels should be reviewed monthly and adjusted based on actual demand patterns, supplier reliability changes, and seasonal factors. Over time, better data leads to lower safety stock requirements.
Pro Tip
Most ecommerce businesses maintain safety stock equal to 15-25% of average monthly sales for their top 20% of products.
Key Takeaways
- Calculate safety stock based on demand variability and lead time
- Review safety stock levels monthly
- Focus safety stock investment on top-selling products
- Track service level metrics to validate safety stock levels
- Reduce safety stock as forecast accuracy improves
