In the case of trade, vast amounts of time and resources are spent transferring information from one document to another. Errors occur frequently; for example 123 becomes 213, 'car parts' becomes 'car ports'. Error rates in excess of 50% have been consistently reported in Letters of Credit. Error rates of 30% are not uncommon in manual processing of Customs entries.
A program must be in production for at least six months for the most harmful error to be discovered.