Pharmacy
Pharmacy counter
The strip, the shelf, and the bill at the counter.
A sale is the strip that left the shelf. Stock moves with the bill.
Batch and expiry sit on the item the cashier picks, so a short-dated box is visible.
A substitute is a choice on the bill, not a whispered swap with no record.
Credit customers have a due the counter can see before the bag is handed over.
The evening total is bills, returns, and the drawer. They live on one screen.
A low item shows before the shelf is empty. The order to the distributor can start from that list.
Returns come back onto the batch they left, when that batch is still the right one.
A new cashier can follow the grid: item, batch, qty, price.
The desk does not replace a pharmacist's judgement. It holds the commercial record of the counter.
The close matches the shop you already run: the queue, the bill, and the night count.