Before you begin the initial data load from a non-SAP system to an SAP system, you have to answer the following questions:
· Which SAP business object types are involved in the target system?
You have to determine which business object type can be allocated the imported data in the destination system. This is important because the business dependencies are mapped across an object model in the SAP System. For example, if you want to transfer data involving sales processing, then business objects Material, Customer, and Sales document are involved.
· How should the data be transferred to the SAP System?
You have to determine the data transfer technique to use for each involved business object type. The techniques BAPI, batch input, and direct input are available for loading the data into the target system. For details of each technique, refer to the description of the Transferring the Data into the SAP System phase.
The key feature of the data transfer is that data can only be transferred from a non-SAP system to an SAP System when it is available in SAP format. For this reason, the data from the non-SAP system initially has to be extracted into a file, and then copied into a transfer file in SAP format. In turn, this transfer file is the foundation for the actual data import into the SAP System.
The entire data transfer usually takes place in five technical phases, which are illustrated in the following diagram.
These phases are described in detail below:
1. Analysis and cleanup of data in the non-SAP system
This phase involves answering three related questions:
Ў Which data exists in the non-SAP system?
Ў How is this data structured (length, sequence)?
This step is required to assign the transferred data to the correct SAP structures later.
Ў Which data can be transferred unchanged, which data has to be supplemented, and which data cannot be transferred at all?
A power company manages its customers for electricity, gas, and water in three separate systems. The company wants to merge these three systems in one SAP System. If customers exist who purchase both gas and water from this company, for example, then the data on these customers may have a different status in the different systems. For this reason, the customer data in each system first has to be cleaned up or merged before it can be transferred to the SAP System.
2. Extraction of data from the non-SAP system
In this step, the determined data is extracted from the non-SAP system to a file. The data in this file still has the format of the non-SAP system. The following options are available for extracting the data:
Ў Using an extraction tool supplied by the non-SAP system
Ў Using the LSM Workbench
Ў Using a database tool
Ў Using the extraction function of a mapping tool
3. Mapping the data in SAP format
Data from a non-SAP system can only be transferred to an SAP System if it is available in SAP format. For this reason, the file containing the data in the non-SAP system format has to be transformed into a transfer file in SAP format.
Because the format of the data extracted from the non-SAP system usually differs from the SAP format of the transfer file, mapping between the different structures is required. To perform this mapping, you will have to analyze both the fields and structures of the data to transfer and the involved SAP structures, in order to determine how the conversion should be performed.
The following options are available for performing the actual mapping:
Ў Writing an ABAP program
Ў Using a commercial mapping tool
Ў Using the SAP mapping tool (available from Release 4.6C onwards)
4. Transferring the data to the SAP System
Before you can import the data from the transfer file to the SAP System, you have to answer the following questions:
Ў In which sequence will the source data be copied to the business object types, and in which sequence will the involved business object types be filled with data?
This question must be answered because dependencies may exist between business object types that require the data to be transferred in a specific order.
Ў Which data transfer technique will be used for the individual business object types?
The following three standard techniques are available for the data transfer:
Calling a BAPI in the appropriate application transfers the data to the SAP System. If BAPIs are used as interfaces to the SAP system, the same technique is used as for the continuous data transfer between SAP Systems or between non-SAP systems and SAP Systems with ALE.
For more information on data transfer using BAPIs, see Process Flow of Mass Data Transfer Using BAPIs.
· Batch input
Batch input is a standard technique for transferring large volumes of data into the SAP System. In the process, the transaction flow is simulated, and the data is transferred as if it were entered online. The advantage of this procedure is that all the transaction checks are performed, which guarantees data consistency.
For detailed information on batch input, please refer to the documentation on batch input sessions under Data Transfer: Overview of Batch Input.
· Direct input
During direct input, the data in the data transfer file is first subjected to various checks, and is then imported directly into the SAP System. The SAP database is updated directly with the transferred data.
Important: You should use BAPIs exclusively to transfer data in Release 4.6A and later.
5. Checking the data
After the data has been transported into the SAP System, it must be checked for completeness. It must be ensured, for example, that the sum of the data transferred into the SAP system is the same as the sum of data from the external system.
SAP created the DX Workbench for Release 3.1 and later to support the transfer of mass data. As of Release 4.6A, this tool provides integrated project management for all the steps involved in transferring data to the SAP System.
In particular, the Data Transfer Workbench offers the following functions:
· Managing and organizing data load projects
· Tools for analyzing the required SAP structures
· Integration of the standard data transfer programs
· Registration and integration of separate data transfer programs
· Support of various techniques for loading data into the SAP System
For more information, please refer to the documentation for the DX Workbench under Data Transfer Workbench.