The number to watch
Breakage per delivery route. Tiles break in transit and most shops absorb it without ever knowing where it happens. Recording breakage as a stock adjustment with the reason, and deliveries with the vehicle, lets you put the two together. It is usually one route, one vehicle or one loading practice, and once it is visible it is fixable — which it never is while the loss is simply written off at the counter.
Boxes and square feet
Tiles are bought by the box and quoted by the square foot, and the box count depends on the size — a 600x600 and an 800x1200 cover different areas per box. Holding the conversion against the item means you can bill either way and both come out right, and the customer sees both figures on the invoice. This is the single most common source of arithmetic error in a tile shop and it disappears entirely once the conversion is on the item.
Batch, shade and the second visit
Tiles from different batches do not match, and a customer who returns for two more boxes six weeks later expects the same shade. Keeping batch as part of the item is how you answer that without opening cartons in the godown. It also prevents the loss where a premium batch is sold at the rate of an ordinary one because both were entered under the same name.
Breakage and site delivery
Tiles break in handling and in transit, and in most shops that loss is absorbed rather than recorded. A stock adjustment with the reason noted turns it into a monthly figure you can act on. Deliveries to a site need the vehicle, the box count and the receiver on the challan, because a short delivery reported a week later is otherwise one person's word against another's.