We Keep Running Out of Stock — But Somehow We Also Have Too Much Stock

Customers keep asking for products you don't have. At the same time, your warehouse is full. Some items are sitting there overstocked while others keep running out — cash tied up in slow-moving stock, while the products customers actually want are unavailable.

It sounds contradictory. It's actually one of the most common inventory problems there is, and it's rarely about having "too much" or "too little" stock overall. It's about having the wrong stock in the wrong place.

Quick Answer: Why Does a Business Have Too Much Stock and Still Run Out?

Overstock and stockouts happen at the same time because inventory planning is based on outdated or disconnected data instead of real, current demand. When purchasing decisions are made from guesswork, spreadsheets or gut feel rather than actual sales patterns and live stock visibility, a business ends up overordering the wrong items while running out of the ones customers actually want. ERP and better demand visibility fix both problems at once, because they're really the same problem.

Why This Happens

Purchasing is based on guesswork. Without clear visibility into what's actually selling, orders get placed on habit or hope rather than real demand.

Sales and inventory aren't connected. Sales might promise stock that doesn't exist, or purchasing might reorder something sales already knows is slowing down.

Stock records aren't accurate, so decisions get made off numbers that don't match reality — more on this in Why Does Our Inventory Never Match What the System Says?

Slow-moving stock isn't caught early. It just keeps sitting there, tying up cash and warehouse space, until someone finally notices months later.

Reorder levels were never properly set — or were set once, years ago, and never revisited as demand shifted.

Multiple branches or warehouses don't share visibility, so one location stocks out while another sits on excess of the same item.

Promotions and seasonal demand aren't factored in, so a campaign or festive season either catches the business under-stocked or leaves it holding leftover inventory afterward.

What Overstock and Stockouts Each Actually Cost

Overstock ties up cash that could be used elsewhere, takes up warehouse space, and risks damage, expiry or obsolescence the longer it sits.

Stockouts cost you the sale itself, plus the customer's trust, and often push them toward a competitor who happened to have it in stock that day.

Know Which Products Are Actually the Problem

Not every SKU behaves the same way, and treating them all with one reorder rule is usually where this starts:

• Fast-moving — sells consistently, needs reliable reorder timing
• Medium-moving — steady but not urgent, more room for flexibility
• Slow-moving — sits for long stretches, ties up cash unnecessarily
• Dead stock — hasn't moved in a long time and probably never will at this price

Reorder Point and Safety Stock, in Plain Terms

Reorder point is the stock level that should trigger a new order — set too low, and you stock out before the new order arrives; too high, and you're carrying excess for no reason.

Safety stock is the buffer held for demand spikes or supplier delays. It should vary by product, not be one blanket number applied to everything you sell.

A Simple Inventory Health Check