Usually caused by a faulty production lots production (Mass Production) to repair or adjust the machine to or caused by the count of bad mistakes as well as from the old job and the new editor as well.
Usually caused by a manufacturing error. Producing a lot (Mass Production) to repair or tuning machines are not perfect. Or by the count of the errors. Including the introduction of new and old to fix it.
Often caused by manufacturing error. Mass production (Mass Production) to repair or tuning machines that are not. Or by counting the defect error. The work includes the old readjusted.