How do you know what to reorder, and when, in a shop?

Why reordering by feeling costs money

Reordering by feeling fails in two directions. A product that sells well runs out before anyone notices, and the customer who asked for it buys somewhere else. A product that sells slowly keeps arriving, and the money you paid for it sits on the shelf.

Both mistakes come from the same cause: the decision is made without looking at how fast each product leaves and how long the supplier takes to deliver.

Start with the sales rate of each product

The sales rate is how many units of a product leave in a period, such as a week or a month. It comes from the sales you already record, as long as every sale, at the counter or in a message, is registered as a stock movement.

Turnover tells the same story from another side: how many times the stock of a product is sold and replaced in a period. A high turnover means the product deserves attention first, and a low one means it deserves a question before the next purchase.

Seasons, holidays and promotions change the rate. Compare the same period of different years when you can, instead of trusting only the last few weeks.

Minimum stock and the time the supplier takes

The minimum is the balance at which you should place a new order. A common way to think about it is to take the sales during the time the supplier needs to deliver and add a safety margin for the days when sales run above average.

If a product sells six units a week and the supplier takes two weeks, twelve units go out while you wait, so the minimum has to be above twelve. The margin depends on how reliable the supplier is and on how much a missed sale costs you, and it is a choice of each business.

The maximum matters as much as the minimum. It is the balance above which buying more only ties up money, takes shelf space and, for perishable goods, risks a loss.

• Sales rate per week or per month
• Days the supplier takes to deliver
• A safety margin chosen for each product
• A maximum, so a purchase does not become a surplus

What not to reorder

Reordering is also deciding to stop. Products that did not sell for a long time, or that sell only when discounted, deserve a review: a promotion to clear them, a return to the supplier when the agreement allows it, or a removal from the catalog.

For goods with an expiry date, use first what expires first, and look at the batches close to the end of their shelf life before buying more of the same product.

Why the conversations with customers belong to this decision

Many sales of a shop start in a message, and the questions that do not become a sale are information too. When customers ask more than once for a product you do not carry, or for a size that is always out, that is a signal to buy, even if the sales numbers do not show it yet.

It also works the other way. If the person answering the customer sees the available balance while talking, the answer is honest from the first message, and you avoid promising what is not on the shelf.

A short weekly routine

Once a week, spend a few minutes on three lists: the products below the minimum, the products at zero and the products that did not move. The first becomes the purchase order, the second is checked against the questions of customers, and the third is discussed before any new purchase.

Write down what you decided and why. After a few weeks, the notes show which minimums were too high or too low, and the numbers improve with each round.