Packing, handling units and SSCC labels

The pack levels of an ASN are only as good as the packing data behind them. A handling unit (HU) is a physical unit, packaging material plus contents, with its own identification number (the external ID, EXIDV). For EDI customers that number is usually an SSCC, the 18-digit serial shipping container code from the GS1 standards, printed as a GS1-128 barcode on the package label. The SSCC on the label, the SSCC in the 856 and the SSCC in the receiver's scan must be the same number, or the receiving dock cannot match the package to the ASN.

Where Contoso's handling units come from

Delivery 80001234 is EWM-relevant, so packing happens in embedded EWM in warehouse 1710. Pickers pick into pick handling units; at packing work center PK01 the packer creates shipping handling units with a packaging material, moves the alternators in, weighs and closes each HU and prints its label (course sap-ewm-203). The reference packing result from sap-sd-204 is the one Great Lakes sees in the ASN: two pallets of 24 and one carton of 2.

SSCC numbering in SAP

SAP's documentation for EWM describes SSCC number assignment directly: you can assign SSCCs uniquely when handling units are created; the packaging material controls whether the system assigns one automatically; the number range is determined by warehouse number, set up under Extended Warehouse Management > Cross-Process Settings > Handling Units > External Identification > SSCC Generation; and you need a GS1 company prefix (SAP's text calls the basis number ILN2) before you can generate them. SSCCs can also be assigned externally and checked against an external number range. For Contoso, the packaging materials for fleet pallets and cartons are set to draw SSCCs, so every shipping HU at PK01 gets one when it is created.

When the HU data reaches the delivery

With EWM, the HUs are created in the warehouse, and the ASN is built from the delivery in SAP S/4HANA. SAP's handling unit documentation for EWM describes HU-related data, such as electronic product codes, being sent from EWM to the delivery during goods issue so that advanced shipping notifications can carry it by IDoc, and being adjusted when an HU changes on the EWM side. Contoso's CMQ tests showed the same for packing: the final HUs of delivery 80001234 were complete on the delivery after goods issue. That is a strong argument for triggering LAVA at goods issue (Lesson 5): before goods issue, delivery 80001234 may not yet show the final packing, and an ASN built from it would carry no packages or the wrong ones.

Packing can also nest. If Great Lakes ever asked for cartons of four on each pallet, the pallet would be a higher-level HU whose E1EDL44 lines point to the cartons' external IDs instead of to a delivery item, and the 856 would use a tare level (T) for the pallet and pack levels (P) for the cartons. Many guides keep structure code 0001 and make the tare level optional; the guide decides, and the map must handle both shapes if the warehouse sometimes ships loose cartons.

Packing rules that protect the ASN

• Make packing mandatory where the partner needs pack levels. SAP lets packing be optional per delivery item category. If Great Lakes requires an SSCC on every package, an unpacked delivery must not be goods-issued, and testers should prove it is blocked.
• Print labels only from closed HUs. A label printed before the last item is packed shows the right SSCC but the wrong contents.
• Repack before goods issue, never after. After goods issue the ASN may already be at the customer; a repack changes SSCCs that the dock is about to scan.
• Keep packaging materials clean. The packaging material decides SSCC assignment and drives the 856 package type and tare weight; a wrong one gives a valid ASN with wrong physical data.
• Own the company prefix. The GS1 company prefix and the SSCC number range belong to master data governance; two warehouses drawing from one range can issue duplicates.