A school running breakfast for around two hundred children, which is a small number in a city and a considerable number on an island with two boats a week.
The kitchen had been shopping at the counter every second day, which meant whoever went was competing with the rest of the island for the same eggs. We took their list, worked out the weekly quantity, and started bringing it as a separate lot on each boat.
That changed our buying more than theirs. Knowing that two hundred and forty eggs and eleven kilograms of flour are already sold before the boat lands means the rest of the island's supply is what is left over rather than what is guessed.
The invoice goes in once a month with GST and is settled by transfer. It has run for three terms without anybody having to ring anybody at seven in the morning.