Map an EDI 850 purchase order into an ERP system

Verified steps

1. Receive the EDI 850 X12 transaction set from the trading partner via the agreed transport (AS2, SFTP, or VAN); validate the envelope segments (ISA/GS/ST) and acknowledge at the functional acknowledgment level with an EDI 997.
2. Parse the 850 segments into a structured representation: BEG (order header: PO number, PO type, date), PO1 (line items: quantity, unit price, UOM, item identifiers), CTT (control totals), and relevant qualifier-based segments (REF for references, DTM for dates, N1 for party names/addresses).
3. Map trading-partner-specific values to ERP internal codes using a cross-reference table: partner's item number (IA qualifier) to ERP material number, partner's ship-to GLN to ERP plant/storage location, UOM code (UN/EDIFACT or X12) to ERP UOM.
4. Create the purchase order in the ERP via the appropriate API or IDoc (ORDERS IDoc for SAP, purchase order import for Oracle/D365), populating header fields from BEG and party segments and line fields from each PO1 loop.
5. Send the 855 Purchase Order Acknowledgment back to the trading partner after successful ERP creation, confirming or modifying quantities and dates; store the 850 transaction set ID for audit and dispute resolution.