Inventory Management for Grocery Shops: Stop Running Out (and Stop Overbuying)

Stock is the biggest pile of money in your shop, and it sits on shelves where you cannot see it working. Too little and you lose sales and customers walk next door. Too much and your cash is frozen in goods that expire, get damaged or sit for months. This guide shows how small shops control both, with a simple reorder formula, a calculator you can use on this page, and a weekly routine that takes about an hour.

The two enemies: running out and over-buying

Running out costs you more than the one missed sale. A customer who cannot find atta, ghee or tea today will try your neighbour tomorrow. Research on US grocery shelves illustrates how common this is: NielsenIQ's 2021 out-of-shelf report estimated that out-of-stock items cost fast-moving consumer goods retailers about 7.4% of sales that never happened, as reported by Supermarket News. We do not know of a published Pakistani figure, but any shopkeeper can recall asking a supplier for an item "ab nahin hai".

Over-buying hides in plain sight. A bargain bulk offer feels like a win until you count the months the extra cartons sit on the shelf, take up space, get dusty, approach expiry and tie up cash you needed for a supplier's payment. Some products also simply spoil: US industry surveys have reported overall store shrink (loss from spoilage, damage and theft) of around 3% of sales, rising to about 5% for produce while dry goods in the centre of the store lose far less, closer to 1%. Those are US figures, but the pattern is true everywhere: fresh and short-dated goods leak the most money.

The aim of stock control is not to hold more or less. It is to hold the right amount of each item.

Step 1: Sort your items into A, B and C

You cannot give the same attention to 500 products. Sort them by how much money they bring in:

• A items are your few best sellers (often roughly the top 20% of products, bringing in about 80% of sales): sugar, atta, rice, cooking oil, tea, milk, ghee, daal. Never run out of these.
• B items are steady sellers. Watch them monthly.
• C items are slow movers and long-tail items. Keep a small amount and do not over-order.

Write your A list on a card and keep it at the counter. These 20 to 30 items deserve most of your stock attention.

Step 2: Know your reorder point

A reorder point is the stock level at which you place a new order, so that the new stock arrives just before you run out. The basic formula is widely used in inventory management (see, for example, this guide to reorder points and safety stock):

Reorder point = (average daily sales × lead time in days) + safety stock

• Average daily sales: how much of the item you usually sell per day.
• Lead time: the days between ordering and the goods being on your shelf.
• Safety stock: a buffer for days when sales are higher than usual or the supplier is late.

Example. You sell 20 kg of sugar a day. Your supplier delivers two days after you call. You want a buffer of 10 kg for busy days. Reorder point = (20 × 2) + 10 = 50 kg. When the shelf and store together hit 50 kg, you order. By the time the delivery arrives, you will have about 10 kg left, which is your buffer.

Reorder point calculator

Use the same units you sell in. For sugar and atta that is kilograms; for oil it is litres; for biscuits it is packets or cartons.

How much safety stock?

Start simple: keep one extra day of sales for A items that are rarely late (for sugar at 20 kg a day, that is 20 kg), and two or three days for items your supplier delivers unreliably or that sell out fast in festival months. If you want a more careful method, a standard formula multiplies the day-to-day variation in your sales by a service-level factor (for example, 1.65 for a 95% chance of not running out) and the square root of your lead time. A shop whose sugar sales swing by about 4 kg from day to day, with a two-day lead time, would hold 1.65 × 4 × 1.41 ≈ 9.3 kg. That is close to the 10 kg buffer we used above.

Step 3: Decide how much to order

When you reach the reorder point, how much should you buy? Consider:

• Cover a set number of days. For most A items, 5 to 10 days of sales. For slow C items, 2 to 4 weeks, but only as one small order.
• Round to the supplier's pack. If sugar comes in 50 kg bags and you need 100 kg, order two bags. For cartons of 24, order in whole cartons.
• Weigh the bulk discount. A 3% discount on a bigger order helps only if you will sell it before it expires. Frozen cash has a cost too.
• Check your cash. Never pay a supplier from money you need for tomorrow's A items.

Step 4: FIFO and expiry

FIFO means first in, first out: the oldest stock sells first. In a shop this is a habit, not software:

1. When new stock arrives, put it behind or under the older stock, never in front.
2. Check expiry dates when you receive goods. Refuse items with very short remaining life, or negotiate the price.
3. Once a week, walk the shelves for items expiring within 30 days and move them to the front.
4. Create a near-expiry corner with a small discount, so those items sell before they become a total loss.
5. Write the expiry month on the carton with a marker when you open it.

A discount on an item two weeks from expiry is almost always better than throwing it away. Even at cost price you recover your money, and at a small profit you earn something.

Step 5: A simple receiving routine

Many stock errors begin at the door. Whenever a delivery arrives:

• Count the cartons and bags against the supplier's bill before the delivery person leaves.
• Check quality, damage and expiry on a few boxes from each lot.
• Record the cost price of each item as you receive it, because your profit depends on it.
• Note any shortage on the bill and have it signed.
• Put it on the shelves with FIFO order in mind.

Step 6: Count a little every week

Do not wait until a yearly stock-take. Count some items on a schedule:

When the counted stock differs from the recorded stock, write down why: damaged, expired, given as a free sample, spilled, wrong entry, or unknown. A pattern in the "unknown" column is your early warning of theft or process problems. Treat a mismatch as a clue to fix, not a reason to blame someone on the spot.

Step 7: Handle bags, cartons and loose items properly

The most common recording mistake in grocery is mixing units. Always keep stock in one base unit (kilograms, litres or pieces) and convert the rest:

• A 50 kg bag = 50 kg. Selling 2.5 kg leaves 47.5 kg.
• A carton of 24 bottles = 24 bottles. Selling 5 loose bottles leaves 19.
• When you break open a carton to sell loose, you do not create stock; you only change how it is sold.

If your system or notebook cannot convert, you will see phantom stock (the book says 50 kg, the shelf says 38) and phantom shortages. This is a key test to apply when you choose POS software.

Step 8: Deal with dead stock

Dead stock is stock that has not sold for a long time, say 60 to 90 days for a fast category like packaged food. Do not ignore it; the longer it sits, the harder it is to sell and the more it costs you in space, cash and risk.

1. Find it. List items with no sales in the last 60 days, using a sales report if you can.
2. Move it. Place it at eye level or next to a fast seller.
3. Bundle it. "Buy 2 get 1 half price" on an item with a decent margin.
4. Return it. Ask the supplier whether they take back slow lines or exchange them for fast ones.
5. Cut your losses. Sell at cost or slightly under. Releasing Rs 20,000 of cash and shelf space beats saving a Rs 3,000 margin you will never earn.
6. Learn from it. Do not reorder that item until you know why it stopped selling.

The numbers to watch every month

Stock days

Stock days = value of stock at cost ÷ cost of goods sold per day. It tells you how many days your stock would last if you stopped buying. Example: stock worth Rs 800,000 at cost, and daily sales of Rs 40,000 at a 10% gross margin (so cost of goods sold is about Rs 36,000 a day) means 800,000 ÷ 36,000 ≈ 22 days of stock. If your suppliers deliver in two days, 22 days is far more than you need, and the extra cash could be paying bills.

Out-of-stock count

How many A items were out of stock this week? Zero is the goal. Write down every time a customer asks for an item you do not have; that is the cheapest market research you will ever do.

Expired or damaged stock

Add up the cost of items you threw away this month. If it keeps rising, you are over-ordering short-life goods or not following FIFO.

Your weekly one-hour stock routine

1. 10 minutes: count all A items and fix any differences.
2. 10 minutes: walk the shelves for expiry within 30 days; move to the near-expiry corner.
3. 15 minutes: check what is below its reorder point and make one combined order per supplier.
4. 10 minutes: read the list of customer requests you could not fill and add those items.
5. 15 minutes: review last week's price changes from suppliers and update your shelf prices.

How Dukaan POS helps

Dukaan POS reduces stock automatically with every sale, in the right unit whether you sell by the kilo, the 5 kg pack or the 50 kg bag. You can set a minimum level per product and see low-stock and expiry alerts in one notification list, record stock counts and corrections with a history of what changed and why, and view the value of your stock in the reports. The software does not decide your reorder quantities for you, but it makes the numbers in this guide, such as daily sales and current stock, one tap away. Start a free 7-day trial and enter your A items first.

Sources and further reading

• Cleverence: Calculating reorder point with safety stock Reorder point and safety stock formulas.
• Supermarket News: Grocery retailers, customers paying the price Trade coverage including out-of-stock data. US figures.