The $1.75 Trillion Problem
IHL Group research estimates that retail inventory distortion — the combination of stockouts and overstock — costs global retailers $1.75 trillion annually. In the US alone, out-of-stocks cost retailers approximately $145 billion in lost sales each year, while excess inventory ties up capital and eventually requires markdowns that erode margin.
These are not problems unique to large retailers. A small boutique clothing store with 500 SKUs or a specialty food shop with 300 products faces the same dynamics: run out of something popular and lose the sale; over-buy something slow and watch it sit. The discipline to avoid both requires systems.
Understanding Your Inventory Metrics
Days of Supply
Days of supply tells you how many days your current stock will last at the current rate of sale. If you have 60 units of a product and sell 4 per day, you have 15 days of supply. If your supplier takes 7 days to deliver, you need to reorder when you have 7–10 days of supply remaining — not when you run out.
Sell-Through Rate
Sell-through rate measures what percentage of received inventory has been sold within a defined period. A 90% sell-through in 30 days is excellent. A 30% sell-through in 60 days signals a problem item that needs promotion or markdown before it becomes dead stock.
Stock Turn (Inventory Turnover)
Stock turn measures how many times your entire inventory is sold and replaced per year. A clothing store might target 4–6 turns per year. A grocery store targets 12–26 turns. Low stock turn means capital is sitting idle in slow-moving product; high turn means efficient use of inventory investment.
Setting Reorder Points
A reorder point is the stock level at which you place a new order. The formula: (Average daily sales × Lead time in days) + Safety stock.
For a product selling 5 units per day with a 7-day lead time and a safety stock of 10 units: reorder point = (5 × 7) + 10 = 45 units. When stock drops to 45, order more.
OneScale calculates reorder points automatically based on your sales history and configured lead times, sending alerts when any product crosses its threshold. No manual monitoring required.
Managing Seasonal Inventory
US retail is heavily seasonal. Holiday season (November–December) can represent 20–30% of annual revenue for many retailers. Summer and back-to-school create secondary peaks. Planning inventory for seasonal peaks requires looking at prior year performance — what sold, what was left over, what ran out.
OneScale's year-over-year comparison reports show sales by product for the same period last year, providing the data foundation for seasonal purchase planning. Buying 20% more of last year's top sellers and 20% less of last year's slow movers is a data-driven approach that beats gut feel consistently.
Dead Stock: Prevention and Recovery
Dead stock is inventory that has not sold in 90+ days and shows no sign of moving. It ties up cash, takes up shelf space, and usually ends up being written off or liquidated at a loss. Prevention: tighter initial buy quantities for unproven items, weekly sell-through monitoring, early markdown decisions when items show low sell-through in the first 30 days.
Recovery options: bundling with fast-moving items, targeted promotions to loyalty customers, returns to suppliers (where contractually possible), liquidation through off-price channels. OneScale's slow-mover report identifies items below the sell-through threshold weekly, giving management time to act before the problem compounds.
Shrinkage Control
US retailers lose approximately 1.4% of revenue to shrinkage annually — employee theft (35.7%), external theft (35.7%), vendor fraud (5.4%), and administrative error (21.3%) according to the National Retail Security Survey. Role-based POS permissions, regular cycle counts, and transaction audit logs address all four categories.
Conclusion
Inventory management is cash management. Every dollar sitting in slow-moving stock is a dollar not available for marketing, staffing, or expansion. Every stockout is a sale permanently lost. The retailers who manage inventory systematically — with reorder points, sell-through monitoring, and shrinkage controls — outperform those who manage by shelf-walking and intuition at every scale of operation.
