The last step in creating a DMEE format tree is to define how data is to be mapped. Outgoing and incoming DME files represent opposite cases regarding the data mapping:
Based on the tree type of your format tree, the system selects all R/3 fields that are predefined for the particular application. These fields form thesource or target field inventory and are made available to you when you do the data mapping.
When you define your tree structure, you must link the fields in your file format to the corresponding fields in the R/3 System. This enables the DME Engine to extract, in the case of outgoing DME files, the required data from the appropriate fields when you later generate a file. For incoming DME files, just the opposite is true: you map how the incoming data is to be filled in the corresponding R/3 fields.
There are several mapping procedures, and they differ for outgoing and incoming files. The most common procedures are direct reference to R/3 fields or specification of a constant. You can also define more complicated mapping rules by includingconditions, aggregation, or exit modules. You may also need to convert the format of your data based on a number of available conversion rules.