Data Migration

[Former Member]

Hi,

Please tell me what is the meaning of Data migration And what type of work we have to do as an abaper

[former_member156446]

Hi Santosh, in data migration.. data by some means need to reach the target system... either file,IDOC, BAPI, RFC..

as an abaper our work might be to write the extracts in the source system.. and write the load tools to load the data into target system..

Either BAPI... IDoc... LSMW might be used to load the data..

[Former Member]

Hi,

Data Migration : Transfer of Data from Non-SAP systems (Legacy applications) to SAP systems using DATA transfer technologies and tools provied by SAP.

Its a costly Process because u need to develop conversion programs, deal with lots technical details and differnt technologies, also data volume depend on project volume .

Steps required for Data Migration :

1. Determine which business objects are to transfered.

2.Unload data from legacy system to files.

3.Determining required fields of source and target systems.

4.Mapping source and target fields.

5.Analyzing and cleaning legacy data.

6.Determing what data transfer method/tools should be used.

7.Configuring Data transfer tools - Creating projects,Stting field rules n generating data transfer programs.

8.Testing - Testing data transfer using test data.

9.Convert extractd and cleaned data into the structures of the transfer file (File in SAP format).

10.Final Data Migration.

11.Checking the results with migration statistics.

SAP provides following techniques for Data Migration :

1.BDC Batch Input Session and Call Transaction.

2.SAP supplied Batch Input and Direct Input Programs

3.BAPI/RFC.

4.ALE/IDoc.

SAP provides following tools for Data Migration :

1. Data Transfer Workbnch

2.LSMW Legacy System Migration Workbench.

3.CATT Computer Aided Test Tool

4.IS-U Migration Workbench.

How Data Migration Works :

1.Data to be migrated is stored in database situated either on PC or on Legacy Application Server.

2.The first step is to extract this data from Legacy aapln 's database n put it in either tab delimited text file or any spreadsheet. This data is then cleaned to remove any existing inconsistencies.

3.The data stored in these files are in Legacy Format.This data must be arranged in SAP format.So, next step will be to convert this data to SAP format.

4.After the conversion, actual data migration is done by using any one of SAP provided technologies i.. BDC, Direct Input or BAPU/IDoc. This can be done by using anyone of SAP provided data transfer tools or by developing custom data migration programs which use above mentioned technologies.

5The data is now migrated to SAP system.

[Former Member]

data migration can done by LSMW,BDC,BAPI, ALE and DI.

SAP Data Migration with LSMW

No ABAP effort are required for the SAP data migration. However, effort are required to map the data into the structure according to the pre-determined format as specified by the pre-written ABAP upload program of the LSMW.

The Legacy System Migration Workbench (LSMW) is a tool recommended by SAP that you can use to transfer data once only or periodically from legacy systems into an R/3 System.

More and more medium-sized firms are implementing SAP solutions, and many of them have their legacy data in desktop programs. In this case, the data is exported in a format that can be read by PC spreadsheet systems. As a result, the data transfer is mere child's play: Simply enter the field names in the first line of the table, and the LSM Workbench's import routine automatically generates the input file for your conversion program.

The LSM Workbench lets you check the data for migration against the current settings of your customizing. The check is performed after the data migration, but before the update in your database.

So although it was designed for uploading of legacy data it is not restricted to this use.

We use it for mass changes, i.e. uploading new/replacement data and it is great, but there are limits on its functionality, depending on the complexity of the transaction you are trying to replicate.

The SAP transaction code is 'LSMW' for SAP version 4.6x.

For those with the older SAP version (4.7 and below), the data migration programs might not have been pre-loaded.

You can download the LSMW at no cost from SAPNet under Services, SAP Methodology and Tools, category Tools.

If you are an existing SAP customer with an OSS ID, you can access the SAP Service Marketplace to download the LSWM for your Basis teams to install to your SAP system: http://service.sap.com/lsmw

The LSM Workbench carries out the following tasks:

Reads the transfer data from one or more files (for example, spreadsheets, sequential files etc.)

Converts the data from the source format into the target format

Data Transfer

When you need to load information into an SAP R/3 system from a legacy system, a set of tools that falls into the Data Transfer catagory are used. Between 3.1H and 4.6C there were major changes in this area of SAP. The old Data Transfer Workbench can be used, or you can combine the new tools with programs that you write to effectively manage a data transfer project. SAP offers The Data Transfer Guidebook www.saplabs.com/dx to help guide users through the process.

Determining when to use Data Transfer technology

Essentially, if Data Transfer technology is not used, the data must be manually entered. Manually entered data will, as a rule, be cleaner and cause fewer problems in the future. A number of factors go into the choice between manual entry of information vs. Data Transfer . Any large group of records (say 2000 or more) will probably need to be automated. Anything less that 2000 can probably be manually input in less time than it will take to write and correctly test a conversion program, convert the data into a QA environment, test and adjust the conversion, then convert the data into your production system.

However, another factor is time available at go-live.

For BAPI's for mass data transfer follow this link

http://help.sap.com/saphelp_nw04/helpdata/en/4c/4c0e8a725311d396a80004ac96334b/frameset.htm

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[Former Member]

Hi Santosh,

For your kind information:

I have seen all your Questions and the Questions are not only answered by PAVAN but also by others. But what i have seen is you are rewarding points to Pavan only, and all the questions which is answered by Pavan is not that much good which is answered by others and some answers are same to others....

so you both of them are playing not only with SDN but also with us, as we are spending time in answering questions.

So its a humble request stop playing, otherwise this mail can be forwarded to SDN community which can sue your happines and makes you to forget SAP.

Pavan beaware while you answer Santosh.

Hope you got it.

thanks

abdul.

Edited by: Mohammed Abdul Samee on May 6, 2008 3:15 PM

[Former Member]

Hi Santosh,

For your kind information:

I have seen all your Questions and the Questions are not only answered by PAVAN but also by others. But what i have seen is you are rewarding points to Pavan only, and all the questions which is answered by Pavan is not that much good which is answered by others and some answers are same to others....

so you both of them are playing not only with SDN but also with us, as we are spending time in answering questions.

So its a humble request stop playing, otherwise this mail can be forwarded to SDN community which can sue your happines and makes you to forget SAP.

Pavan beaware while you answer Santosh.

Hope you got it.

thanks

abdul.

Edited by: Mohammed Abdul Samee on May 6, 2008 3:19 PM