An empty shelf loses sales; a full one of what does not sell ties up money. Between these two extremes is data-driven inventory management, which uses numbers instead of intuition to decide how much to order and when. Two concepts do almost all the work: reorder point and safety stock.
The problem of ordering by instinct
"Order more when it looks low" is a recipe for stockout or excess. Without clear rules, each product is managed differently depending on who is on duty, and the result is unbalanced warehouses — short of what sells, overstocked with what does not.
Reorder point: when to order
The reorder point is the stock level that triggers a new order. It is calculated from two things: how much you sell per day and how long the supplier takes to deliver. If you sell 10 a day and delivery takes 5 days, you need to reorder when you have 50 — otherwise you run out before the new one arrives.
Safety stock: the margin for the unexpected
Demand varies and suppliers run late. Safety stock is the extra cushion that protects you from those surprises. The more unpredictable the demand or the supplier, the bigger the cushion. It is the balance between the risk of stockout and the cost of holding idle stock.
The 80/20 rule of inventory
- A few products generate most sales: focus attention on those first.
- Many products sell little: the same care is not worth it for all.
- Classify by importance and apply tighter rules where the impact is greater.
You already have the data you need
Sales history and delivery lead times — which any business has — are enough to calculate sensible reorder points and safety stock. You do not need an expensive system to start; you need to use the numbers already in front of you.
In practice
Pick your most important products and calculate, for each, the reorder point and safety stock from history. That alone reduces stockouts and excess at the same time. Does your replenishment follow data-based rules, or the instinct of whoever is looking at the shelf?
