Warehouse and sales system with POS, stock and expiry by lot

A warehouse and POS system is mostly about getting stock movements right: every item that arrives, moves, sells or expires must change a number, and for food, medicine or cosmetics each change must be tied to a lot with an expiry date. I build this as custom software with a warehouse side, a sales side and a simple shop till, all reading the same stock.

What this looks like in practice

Goods receipt is the first screen. You enter or scan the supplier document, and for each line you record item, quantity, lot number and expiry date. The system adds the lot to the location where it was shelved.

When an order is picked, the system suggests lots by FEFO and shows the expiry next to each one. A picker can override it, and the override is logged. At the shop till, the cashier scans the item and the system takes stock from the earliest-expiring lot automatically.

What I build

• Items with units, barcodes, supplier, and price lists.
• Locations and stock by lot with expiry date.
• Goods receipt, transfers between locations, stock counts and adjustments with a reason.
• Sales orders, delivery notes and invoices for the warehouse side.
• A touch-friendly POS screen with barcode scanning, cash and card tender types, and a daily close.
• Expiry report: lots expiring within a window you choose, and a low-stock list.
• Roles, so cashiers cannot change prices or edit received stock.

Where this goes wrong

Three things cause most of the problems. First, units: an item bought by the case and sold by the piece needs a defined conversion, or the numbers drift. Second, returns: a returned item should go back to its original lot or to quarantine, not to a random one. Third, counts: if staff do not record the real count, the system trusts a wrong number. I add a count screen and a variance report so mistakes are visible.

Buying off the shelf

Plenty of good inventory and POS products exist. Choose one if your rules are standard and the monthly fees are acceptable. A custom build fits when you need lot and expiry logic that a till app does not provide, when two or three tools must be stitched together, or when you want a fixed price and ownership instead of per-seat billing.

How it goes live

I need your item list, your current stock with lots if you have them, and a description of how goods arrive and leave. I import this, set up the till hardware you already have, and do a stock count together on go-live day. One fixed price is agreed before work starts. Monthly maintenance for fixes, updates and support is optional.