LSMW is a tool used to tranfer data from legacy system to R/3 periodically or once.It supports conversion of data and Batch Input,BAPI,IDOC or Direct Input can be used as the method for transfer of data.Total of 26 processing steps are available in LSMW ,In case of data transfer using Batch Input only 14 steps are required.
Execute the transaction LSMW to start transfer of data,Before using the LSMW we should have good knowledge about the business object and the fields that will be transferred.
The main screen of LSMW provides wizard-like step-by-step tasks, To complete your data conversion, you need to execute these steps in sequence. Once a step is executed, the cursor is automatically positioned to the next step.
Note that these steps may look different depending upon your Personal menu settings. You could make step numbers visible by ‘Numbers on’ icon or hidden by ‘Numbers off’ icon. You can execute a step by double-clicking on the row. Toggle icon ‘Doubleclick=Display’ or ‘Doubleclick=Edit’, makes the step in ‘display’ mode or ‘change’ mode.
There are 14 steps that are normally used and these are.
1) Maintain Object Attributes.
2) Maintain Source Structures.
3) Maintain Source Fields.
4) Maintain Structure Relations
5) Maintain Field Mapping and conversion rules .
6) Maintain Fixed Values,translations ,user defined routines.
7) Specify Files .
8) Assign Files .
9) Read DATA.
10) Display Read Data.
11) Convert Data.
12) Display Converted Data.
13) Create Batch Input Session.
14) Run Batch Input Sesion.
1) Maintain Object Attributes.
In this example, you will be updating the customer master records with the help of recording a transaction (XD02).
a.Choose radio button Batch Input Recording and
bclick on the recording overview icon to record the R/3 transaction.
c.Enter the Recording nameasXD02_REC,the description as Customer Master Updates Recording, and
d.the transaction code as XD02(FS00 in case of gl accounts)
Once the transaction is completed, R/3 records the flow of screens and fields and saves the information,
2) Maintain Source Structures.
Give a name and a description to the source structure
3) Maintain Source Fields.
In this step, you need to list what fields are present in the source structure. The easiest way is to click on ‘Table Maintenance’ icon to enter Fieldname, Type and Length for each field
Note that your input file will have four fields as key fields and you need to update three fields in the system
4) Maintain Structure Relations
Execute a step to ‘Maintain Structure Relations’. Since, there is only one Source and Target Structure, the relationship is defaulted automatically
5) Maintain Field Mapping and conversion rules .
In this step, source/legacy fields in each structure are assigned to R/3 fields. It may be done individually for each R/3 field, which being time-consuming for complex structures or we can use automatic mapping utility (Extras > Auto-Field mapping).
We can specify the conversion rule to be used to convert an LS field into the corresponding R/3 field. For this, use predefined conversion rules or create your own conversion rules in the editor.
You may use the buttons ‘Initial’, ‘Constant’, ‘Move’ & ‘Fixed Value’ to assign different values. You may also assign different rules by using the button ‘Rule’. automatic mapping utility (Extras > Auto-Field mapping).
6) Maintain Fixed Values,translations ,user defined routines.
7) Specify Files .
In this step, we define how the layout of the input file is. The input file is a [Tab] delimited with the first row as field names. It is present on my PC (local drive)
Create an Excel file with your data and save it as a Tab-delimited text file on your local drive.
8) Assign Files .
Execute step ‘Assign Files’ and the system automatically defaults the filename to the source structure.
9) Read DATA.
In this step, LSMW reads the data from the source file (from your PC’s local drive).
10) Display Read Data.
This step is optional. If required, you can review the field contents for the rows of data read
11) Convert Data.
This is the step that actually converts the source data (in source format) to a target format. Based on the conversion rules defined, source fields are mapped to target fields.
12) Display Converted Data.
Again this is an optional step to view how the source data is converted to internal SAP format
13) Create Batch Input Session.
Once the source data is converted in an internal format, you can create a batch session to process updates .
14) Run Batch Input Sesion.
You can execute the BDC session by Run Batch input session. Executing a batch input session is a standard SM35 transaction for managing BDC sessions. Once you have successfully executed the batch input session, the customer master records are updated in the system. You can confirm this by viewing the customer master records (XD03).
Note! Browsing thru these 14 steps, you may get a feeling that this is a very lengthy and time-consuming activity. However, for the purposes of demonstration, I have made it detailed. Although it looks lengthy, actually it takes hardly few hours from start-to-finish! After playing around with few simple LSMW scripts, you will find it so easy to change and create more complex ones.