IDoc Extensions and Enhancements: Custom Segments and Extension Types (WE30, WE31, WE82)

Keep this: job aid

IDoc extension checklist

• Decide first: constant or derivable → middleware mapping; standard field exists → fill it; only in SAP → extension.
• WE31: segment type Z1..., fields from data elements, character formats agreed with the partner, documentation written, then release.
• WE30: extension on the SAP basic type, custom segment under the right reference segment, occurrences set (optional = minimum 0), release.
• WE82: message type + basic type + extension + release.
• WE20: Extension field on each partner that should receive it; WE57 for inbound function modules (direction 2).
• Middleware: reimport the extended structure, extend the mapping; partner spec from WE60.
• Exits: MM06E001 (EXIT_SAPLEINM_002), LVEDF001 (EXIT_SAPLVEDF_002), V56K0001 (EXIT_SAPLV56K_002), MRMH0002, VEDA0001; activate in CMOD.
• Thin include, logic in a tested Z class, reads via CDS views or documented interfaces, ATC clean core checks.
• Regression: golden IDoc comparison, with-data, without-data and partner-without-extension cases.
• Register every extension: reason, objects, data sources, partners, middleware, owners, tests.