How to prevent stockouts and overstock
Updated October 2026 · By Artem Stepanenko, founder of SCAIT
Short answer. Most brands run out of best sellers and overstock slow movers at the same time because they plan from averages that hide both problems. Plan each SKU in each warehouse from clean sales data and real lead times, give your top SKUs more safety stock than the rest, and review reorders on a fixed weekly rhythm.
1. Clean your sales history
Leave out the days a product was out of stock. Otherwise the weak weeks look like weak demand, you order less and the stockout repeats.
2. Use lead times that actually happened
Measure from order to sellable stock on your last few purchase orders, including freight, customs and receiving. Supplier quotes are usually the best case.
3. Plan every warehouse separately
One total across your 3PL and Amazon FBA can look healthy while one location is empty. Each warehouse needs its own days of cover and its own reorder point.
4. Treat SKUs differently
Sort SKUs by revenue (ABC) and by how steady demand is (XYZ). Steady best sellers get tight, frequent reorders and higher safety stock. Erratic slow movers get smaller orders and a lower service level.
5. Review on a fixed rhythm
Once a week, check every SKU against its reorder point and every open purchase order against its expected arrival. Stockouts usually start as a late PO nobody chased.
6. Act on slow movers early
Flag SKUs with more than six months of cover. Stop reordering them, bundle or discount them, or move the stock to the channel where it sells, before storage fees and markdowns eat the margin.
7. Give reordering an owner
In small teams reordering is everyone's second job, so it happens late. One person, or one service, should own the weekly decision.
Want this done for you every week?
SCAIT is a done-for-you inventory management and reorder planning service for brands selling their own products on Shopify and Amazon. Every Monday we tell you what to reorder, from whom, how much and by when. See Reorder Desk (from $490 a month) or compare your options.
Related: How to calculate how much inventory to order · How much inventory to send to Amazon FBA
Questions founders ask.
What is a good in-stock rate for an e-commerce brand?
It depends on your margins and lead times. Set a higher target for your top sellers than for slow movers, and track it per warehouse, not only in total.
What is the difference between a stockout and overstock?
A stockout is having zero sellable units while customers still want the product. Overstock is holding more than you will sell in a reasonable time, which ties up cash and adds storage fees.
What should I do with dead stock?
Stop reordering it, then bundle, discount, move it to another channel or liquidate it. The longer it sits, the more it costs in storage and markdowns.
Do I need software to prevent stockouts?
Not necessarily. A spreadsheet works if someone owns the weekly review. Software or a done-for-you service helps when the catalog or the number of warehouses gets too big to do by hand.