Goods stocked by the piece but only ever sold by the pack: the reference unit disappears from every unit selector.
Keep the reference unit out of sale order lines and start them on a packaging.
Keep the shop from putting loose pieces in the cart when a product may only be sold by the pack.
A warehouse desk inside the session: the stock on hand of this shop and of the warehouses it may see, counted and searched one tap from the register.
Grant the financial discount a customer negotiated without computing it by hand: a plan says how often it is granted, who gets it, on which turnover, how fast the invoices have to be paid and how much each step is worth. Every period, a run shows what each customer did and what he is owed, and once approved it writes the credit note.
Hand the bonus over as points instead of money: the approved run loads an eWallet, a gift card or a loyalty card of each customer with the amount he earned, which he spends on his next order instead of cashing a credit note.
Grant the bonus as a sale order on a service instead of a credit note: the run writes one order per customer, with the amount read from his turnover, and the salesperson can put the same discount on a quotation he is writing, computed in front of him.
Write the bonus for a class of customers or for a level of the segmentation instead of typing a condition: the plan is for the Gold and the Platinum of the B2B class, and one step of it may be reserved to one level, so the same plan grants 1% to a Silver and 2% to a Gold.
Order from a vendor at the till: a request for quotation written line by line -- quantities, units and prices -- on the shop's own desk, confirmed by a manager.
Says which employee wrote the request for quotation, asked the vendor and ordered, and can write the orders as that employee's own user.
Says which employee counted, validated or asked for goods at the till, and can write the stock documents as that employee's own user.