Every Product Every Interval
The frequency with which different part numbers are produced in a production process or system.
If a machine is changed over in a sequence so that every part number assigned to it is produced every three days, then EPEx is three days. In general, it is good for EPEx to be as small as possible in order to produce small lots of each part number and minimize inventories in the system. However, a machine's EPEx will depend on changeover times and the number of part numbers assigned to the machine. A machine with long changeovers (and large minimum batch sizes) running many part numbers will inevitably have a large EPEx unless changeover times or the number of part numbers can be reduced.