13 October 2026

Knowing when to restock without setting up an ERP

Tuesday morning, a customer walks in and asks for the best-selling product. And there is none left. The last box went out on Friday and nobody noticed. Now it means calling the supplier, waiting four days, and telling the customer to come back next week.

If that sounds familiar, you are not alone. In many small businesses stock "lives" in the head of whoever runs the storeroom, in a spreadsheet or in a notebook. It works until that person goes on holiday, or until the business grows a little. And the solution is not necessarily a four-figure ERP.

The real problem: not the stock, the alert

Running out of product almost never happens because of bad counting. It happens because nobody said "time to order" in time. So what needs solving is the alert, not the whole management system.

Three steps you can take this week

1. Pick only the 20 products that matter. You do not need to control the 800 items in the catalogue. List the ones that, if missing, lose you sales or stop the work: the best sellers, the ones with the longest lead time, and the ones that depend on a single supplier.

2. For each one, set two numbers. The minimum (below how many units you reorder) and the order quantity. To work out the minimum, think like this: how many units you sell in a normal week, multiplied by the days the supplier takes to deliver, plus a small safety buffer. If you sell 10 a week and the supplier takes 10 days, the minimum is around 15–20 units.

3. Decide who gets the alert and how. A spreadsheet with a "current stock" column and a "minimum" column can already flag in red what needs reordering. What makes the difference is that the alert arrives by itself (a message or an email) and does not depend on someone opening the sheet.

An example: a hardware shop

Imagine a hardware shop with two employees. They sell screws, silicone, cable ties and plumbing parts; many of these items are used up at a predictable rate. The owner does the inventory "by eye" and orders when he remembers.

With a list of 25 key items and their minimums, every time a sale or a delivery note is recorded, the stock updates. When an item drops below its minimum, a summary arrives in the owner's inbox: "Restock: neutral silicone (4 units), 200 mm cable ties (1 pack)". All he has to do is review and confirm the order with the supplier.

It is not magic: it is having the data in order and an alert that fires by itself.

What to watch

• The data has to be reliable. An alert on a badly counted stock is worse than no alert. Do a physical count of the 20 key products once a quarter.
• Seasonality. August's minimum is not December's. Review it when the season changes.
• Do not automate the order without control at first. Let the alert go to a person, who decides. Once you have had a few months of seeing the alerts are right, you can consider having the order prepared automatically — always with someone validating it.
• Privacy. Supplier delivery notes and invoices contain agreed prices, terms and contact details. If you use an AI tool to read them, check where the data is sent and whether the vendor uses it to train its models. Better that it stays inside the EU and under your control.

Where AI fits

The heaviest part is often entering the data: transferring every supplier delivery note into the stock sheet. That is where AI genuinely saves work: it can read the delivery note (on paper, as a PDF or a photo), extract the items and quantities, and leave them ready to update the stock. ParsIA does precisely that, and it installs on your own servers, so your suppliers' documents never leave your control — the design is written up on the project page.

This article is general information, not advice for a specific case.