LSMW which stands for Legacy System Migration Workbench supports conversion of legacy system data in a orderly and convenient way. Tool allows you to import converted legacy data to SAP.
There are several ways you can import legacy data to SAP using LSMW. Below are few common methods used to migrate legacy data to SAP using LSMW.
Batch Data Input (BDC)
In cut-over phase of the project cycle LSMW conversions are mainly used to import legacy system data to R3. But conversions/migrations can be reused according to requirement.
Transaction to access this migration tool is LSMW. It is a tool that facilitates legacy data migration through a “Data Migration Object”.
Data migration objects are logically segregated under Project and Sub Project hierarchy. For example you can have a Project named “R3 Implementation” with sub objects for each legacy system or Project name for each legacy system and sub project name for each type of data which are migrated. The naming and hierarchical representation depend on the complexity and scope of the requirement.
Example shows how to create a LSMW which creates materials using batch input method. Check my blog on BDC to understand more on batch input method. We would be uploading tab delimited text file with material information which represent legacy data. Batch data recording to material creation transaction (MM01) would be called to upload this data.
Upload file format
Step 1 – Set LSMW Project Name, Sub Project and Object Name.
Go to transaction LSMW and set project name, Sub project name and object name.
Step 2 – Execute LSMW Creation Wizard.
LSMW provide a tool set to create the source data format, convert data, upload data, map source (text file) and target (MM01) and finally create BDC session.
To create a complete conversion/upload all these steps should be completed. Select the step and click “execute” to complete the step. You can move to the next step when you complete all previous steps before it.
How to complete each step shown below.
Step 3 – Maintain Object Attributes
Step 4 – Set Import Method.
Set import method as “Batch Input Recording (BDC)” and record the batch input for transaction MM01. Click on “Recording Overview” button to start recording.
Step 5 – Set recording name and transaction code.
Step 6 – Set Default Values and Prepare Target Structure
Created recording. We will set material description, unit of measure, material group, material style and product hierarchy from text file input data. Industry sector and material type are set with default value.
You can maintain field names and default values of each field by double clicking on the field. Names will help you identify fields easily.
Step 7 – Create Source Data Structures
Set source structure name. This represent the row type of text file.
Step 8 – Maintain Source Fields
Complete the source structure by defining source structure (row type) fields. Easiest way is to select your source structure and click on “Table Maintenance”. Now you can set field names, data type, length and description of each field.
Step 9 – Maintain Structure Relations
Since this project has only one source and one target, system will automatically assign them together. In a more complex projects you may have to manually assign them depending on number of source/target structures.
Step 10 – Maintain Field Mapping and Conversion Rules
Here we map source fields with target fields. That is input file structure with MM01 target.
Select a field and click on “source field” then select the source field.