Trace each batch from material lot to dispatch, and each order to its cost and settlement.

This group runs from makers of snacks, pickles and spice blends to bottlers of squash, soap and floor cleaner, and on to bakeries, caterers, breweries and wineries. Some pack under their own brand. Others cook only against an order. Everything they handle has a shelf life or a serving time, so a late discovery costs real stock and a real customer.

A plant or kitchen working to a recipe runs in batches, whether a vat of fried snack mix, a reactor of shampoo base or a tray of sponge. Only three numbers matter. Quantity issued, quantity made and the amount lost to rejection, spillage or trimmings are written on a clipboard at the stage of loss. Totals are added up after the shift ends, by which time nobody remembers why one vat came up short against its recipe. Accounts see the invoice, never the lot.

Selling adds a record of its own. Stockists phone or message a salesman, and a scheme such as buy ten cartons, get one free runs for a set period. Hospital and hostel kitchens send daily orders against agreed rates, and cake or wedding customers revise the menu, the tiers or the headcount again and again. Returns, leakage claims and extra plates all turn up afterwards, and each must be checked against what was dispatched, promised or served.