PT Barnum is supposed to have said that there is a sucker born every minute. Judging by how frequently suckers (or suction cups) are used on packaging machinery, it is probably more like every second.

Suction cups are pretty cheap, generally only a couple dollars each but I have found that some plants try to makes them last as long as they possibly can. This leads to worn, wear hardened and damaged suction cups. When this happens, the carton, case, label or other component will not be gripped securely. This allows it to slide out of position or even fall off the suction cup completely. These problems will cost far more in lost productivity and rejected product than would ever be saved on the cost of new suction cups.

At a minimum, replace the cups at the least sign of wear. Even better, figure out how long they last. It may be days in some applications, weeks or months in others. Then replace them periodically before they show signs of wear.