Mapping guidelines and proposals you can defend

A mapping guideline (MAG) connects a source MIG to a target MIG and documents how each target node is filled: mapping lines, functions, conditions, constants and code value mappings. SAP Help calls it the runtime artifact you use in the mapping step of an integration application. For Great Lakes, the MAG GLFS_850_to_ORDERS05 maps the 850 MIG to Contoso's ORDERS05 MIG (the extended IDoc from lesson 1).

Three kinds of MAG

• Graphical MAG: Standard holds the core mapping rules; once created it carries the label Base.
• Graphical MAG: Overlay inherits every element of a base MAG and lets you retain, delete or override elements for one partner or use case. Changes to the base flow into overlays automatically.
• XSLT MAG is uploaded as a finished XSLT file instead of drawn.

Create one under Design > MAGs > Create: choose the source MIG, the target MIG, then confirm name, summary and the source and target business context. The new MAG is Draft version 1.0. You can also copy a MAG alone, or copy it with its referenced MIGs.

Drawing the mapping

In the Mapping tab you drag a source node onto a target node. Mapping a group to a group creates one target instance per source instance, so mapping the PO1 loop to the E1EDP01 segment gives one IDoc item per X12 line. Mapping leaves without their groups lets the target structure follow the leaves. Supported cardinalities include 1:1 leaf-to-leaf, group-to-group and leaf-to-group, N:1 leaf-to-leaf, group-to-leaf, and 0:1 constants. Create 1:1 Mappings links identical nodes in two selected subtrees.

Most of the value comes from the details. Value transformations include date-time conversion (BEG05 CCYYMMDD to the IDoc date), string processing, code value mappings (unit EA to Contoso's PCE, local or as a reusable global code value mapping), and functions written in XSLT or XPath, which can be saved as shared code. A conditional mapping uses an XPath condition to control whether a target instance is created. Constants fill fields the partner never sends, such as sales organization 1710, distribution channel 10 and division 00 in E1EDK14. Global parameters read values set outside the mapping, for example headers from the EDI Splitter in Cloud Integration.

Sometimes the two structures are too different to map line by line, for example when the source nests data in a hierarchy the target flattens. For that case Integration Advisor offers pretransformation of the source MIG: a pretransformation script reshapes the source structure at design time so it can be mapped in the MAG, and it supplies a matching runtime artifact so the payload is reshaped the same way when the flow runs. Use it sparingly; most X12-to-IDoc mappings don't need it.

The proposal service

In edit mode, Proposals: Get Proposals flags target nodes for which other users have mapped similar MIGs in a similar business context; Proposals: Select Best Proposal accepts all top proposals at once, or you tick single ones in the mapping list. SAP's data collection page explains what feeds it: when a MIG or MAG is activated, structural content goes anonymously into a knowledge base: node properties, selected code values, qualifications, mapping lines, constants, code value mappings, and XSLT not marked confidential. Names, notes, example values, MIG codelists, administrative data and confidential XSLT stay out.

Proposals are a fast first draft, not a verdict. Other companies' Great Lakes-like partners may map N1 [ST] to a different IDoc partner function, or carry the buyer's part number where Contoso needs its own. Theo's rule: accept a proposal only when the developer can point to the line in the partner's spec that supports it, and record the reason in the mapping element's documentation. For the Great Lakes MAG, proposals filled 41 of 58 target fields; review rejected 6, including one that mapped PO107 (Great Lakes' own part number) to the material field instead of PO109 (Contoso's number under qualifier VP).

Administrators can turn the proposal service off under Settings > MIGs and MAGs > Administrative Settings with Enable Proposal Service. Switching it off stops data collection from then on and removes proposals for the tenant; it doesn't delete data already collected. Nadia, Contoso's security and GRC lead, reviewed the data collection page and accepted the service, with one condition: any XSLT function that embeds partner-specific logic is marked confidential.