Inventory management software tied to the rest of the business
Stock only tells the truth when it moves on its own. Here a goods receipt raises it and a delivery lowers it, so the number on the screen is the number on the shelf.
Stock across locations, batches and serials
Multiple warehouses, batch and serial tracking for anything that needs a history, and stock by style, colour and size for trades where one product is forty things to count.
Reordering before a sale is lost
Minimum levels on the items that move and ageing on the ones that do not, so the fast movers are in stock on a Saturday and the dead stock is discounted while somebody still wants it.
Purchase orders and vendors in the same place
Raise a purchase order against a shortage, receive against the order, and let the vendor bill match what actually arrived.