When mapping a DESADV IDoc to an EDI X12 856, the mapper must extract details like the UPC and customer material number from the item level of the IDoc (E1EDL24 segment) and place them at the appropriate pack level in the 856. These values must align with the correct handling unit (E1EDL37 segment) and the corresponding item within that handling unit (E1EDL44 segment).

The complication lies in correctly associating each E1EDL24 line with the appropriate item in the handling unit, as the items within a handling unit may not follow the same order as they appear on the delivery and can also repeat.

The following diagram illustrates where the data originates in the IDoc and how it should be mapped to the EDI 856.

As shown in the diagram, accurate mapping depends on correctly linking each item’s details from the E1EDL24 segment to its corresponding handling unit and item assignment, ensuring the EDI 856 reflects the true packaging structure. Header level details are a little easier to integrate into the final output.