The selection screen is a scrolling window with all open MO lines for the call line. An MO line is considered open when the quantity shipped on the MO is greater than the quantity consumed plus the quantity returned.

For each selected MO line, one item usage record is created. Internally, each item usage record remains linked to the MO line so it is recognized later when quantities are updated. As a result, if all the items on an MO are not yet accounted for, the MO remains on the list of open MOs to be selected the next time this call item is processed.