SAP EDI Subsystem Architecture and Mapping

The Definition Component

The definition component is where mapping definitions between EDI and IDoc formats are created. This component can run without any connection to the SAP system or its server module. The maps are platform independent. The definition component carries out the following functions.

1. Defines the source structure and destination structure.
2. Maps fields in the source structure to fields in the destination structure.
3. Compiles maps for other platforms.
4. Tests maps.
5. Provides utilities to download and upload IDoc structures, document structures, and maps.

The structure of standard EDI documents for commonly−used standards (ANSI X12 and EDIFACT) is shipped with most EDI subsystems.

The Execution Component
Maps created in the definition component step are executed on the server, which is known as the execution component. The execution component is where the complete environment for executing the maps, trading partner relationships, and other server−related functions are performed. The list of common tasks performed on the server and features commonly found in EDI subsystems is given below.

1. Execution of maps
2. Maintenance of trading partner agreements
3. Configuration of the environment
4. Maintenance of log information
5. Archiving
6. Tools for monitoring the process
7. Tools for restart and recovery of failed transactions
8. Scripts for connectivity with VAN

Mapping Concepts for IDocs and EDI Document Formats

A map is created for every message exchanged with a business partner. Mapping an IDoc to an EDI format requires the following steps.

1.Download the SAP IDoc structure :The IDoc structure is downloaded into the definition component. SAP provides a program named RSEIDOC3 that generates a structured report of the IDoc structure. The report is downloaded to a file and can then be copied to the PC on which the definition component is installed.

2.Define the IDoc structure: The output file can be imported into the definition component to make the IDoc format known to the system. To create the IDoc structure, the software vendors provide a utility program to import the file automatically. The IDoc structure has a control record structure and several data record structures.

3.Define the EDI document structure: Software vendors usually provide the structure of the standard EDI documents.

4.Define the maps:Mapping is the process of linking source fields to destination fields. In complex mapping, values from several fields of the source structure are manipulated in different ways to generate an output value for a field in the destination structure. The systems usually allow manipulation using functions, external program calls, and so on. You must check with your software vendor about the sophistication of the mapping process.

5.Compile the maps: Maps need to be compiled before they can be executed. The compilation process is simple. The system checks the syntax of the map, the consistency of business rules used in the map, and the source and destination data elements in the map. If compilation is successful, the map is ready to be executed.

6.Test the compiled maps: The maps can be tested on the definition system using some test data. An input file is processed through a map to generate the output. The output should be verified manually the data should be in the correct location and in the correct format.

7.Transport the maps: The definition component can usually compile maps for use on other platforms. Thus, if the execution engine resides on UNIX and the definition component is on a PC, the system can generate a compile map for the UNIX system. The compiled map can then be transported to the EDI server system via any file transfer techniques.

8.Execute the maps: The maps can then be executed on the server. During production, the system executes maps on the server.(53.2)