Slabs, blocks and tiles at mandi scale
A single buyer takes slabs by the square foot, blocks by the ton and cut sizes by the piece, often in one transaction and frequently by the container. Holding the unit and conversion on each item is what turns three separate calculations into one bill, and printing both the measured quantity and the wastage allowance as separate lines settles the negotiation before it starts.
Lot is the product
Marble from different lots does not match, and a buyer taking a container expects consistency across it. Each lot as its own item with its own rate and stock is how you answer a shade query without walking the yard — and it stops a premium lot being invoiced at an ordinary lot's rate, which in this trade is a large amount of money.
Despatch across the country
Most of what leaves Kishangarh goes to another state, which means IGST rather than CGST and SGST, and the e-way bill figures have to be right or the truck stops. The treatment switches automatically from the buyer's state on the party, and the value, HSN codes and vehicle details sit on the same record as the invoice.