Diff between LSMW and BDC

[former_member577909]

1) Can you please explain what is the main difference between LSMW and BDC

2) Out of these two methods...which is to be used when...

3) What are all the merits and de-merits of these two methods used in Data transfers

I am very much Thankyful for your time in giving the answers.

Bhaskar

[Former Member]

LSMW and BDC are vastly different.

BDC (Batch Data Communication) is a technology used for data transfer. it is meant for transferring data thru SAP transactions itself. when u use BDC for data transfer, the sequence of steps is the same as when u use standard sap transaction screens for data upload. the only difference is that u can use different options for foreground/background processing.

LSMW on the other hand is a tool that helps migrate data from a legacy system (non-sap system ) to SAP system. it offers u various options to use either batch input, direct input, BAPIs or idocs. it involves a series of some 17-18 steps to migrate data.

BDC:

Batch Data Communication (BDC) is the process of transferring data from one SAP System to another SAP system or from a non-SAP system to SAP System.

Features :

BDC is an automatic procedure.

This method is used to transfer large amount of data that is available in electronic medium.

BDC can be used primarily when installing the SAP system and when transferring data from a legacy system (external system).

BDC uses normal transaction codes to transfer data.

Types of BDC :

CLASSICAL BATCH INPUT (Session Method)

CALL TRANSACTION

BATCH INPUT METHOD:

This method is also called as ‘CLASSICAL METHOD’.

Features:

Asynchronous processing.

Synchronous Processing in database update.

Transfer data for more than one transaction.

Batch input processing log will be generated.

During processing, no transaction is started until the previous transaction has been written to the database.

CALL TRANSACTION METHOD :

This is another method to transfer data from the legacy system.

Features:

Synchronous processing. The system performs a database commit immediately before and after the CALL TRANSACTION USING statement.

Updating the database can be either synchronous or asynchronous. The program specifies the update type.

Transfer data for a single transaction.

Transfers data for a sequence of dialog screens.

No batch input processing log is generated.

For BDC:

http://myweb.dal.ca/hchinni/sap/bdc_home.htm

https://www.sdn.sap.com/irj/sdn/wiki?path=/display/home/bdc&;

http://www.sap-img.com/abap/learning-bdc-programming.htm

http://www.sapdevelopment.co.uk/bdc/bdchome.htm

http://www.sap-img.com/abap/difference-between-batch-input-and-call-transaction-in-bdc.htm

http://help.sap.com/saphelp_47x200/helpdata/en/69/c250684ba111d189750000e8322d00/frameset.htm

http://www.sapbrain.com/TUTORIALS/TECHNICAL/BDC_tutorial.html

LSMW:

The LSM Workbench is an R/3-based tool that supports You when transferring data from non-SAP systems ("Legacy Systems") to R/3 once or periodically.

The tool supports conversion of data of the legacy system in a convenient way. The data can then be imported into the R/3 system via batch input, direct input, BAPIs or IDocs.

Furthermore, the LSM Workbench provides a recording function that allows to generate a "data migration object" in an entry or change transaction.

The main advantages of the LSM Workbench:

• Part of R/3 and thus independent of individual platforms

• A variety of technical possibilities of data conversion:

• Data consistency due to standard import techniques:

Batch input

Direct input

BAPIs (Business Application Programming Interfaces)

IDocs (Intermediate Documents)

The import technique to be used in an individual case depends on the business object.

• Generation of the conversion program on the basis of defined rules

• Clear interactive process guide

• Interface for data in spreadsheet format

• Creation of data migration objects on the basis of recorded transactions

• Charge-free for SAP customers and SAP partners

http://help.sap.com/saphelp_nw04s/helpdata/en/87/f3ae74e68111d1b3ff006094b944c8/content.htm

http://www.sap-img.com/sap-data-migration.htm

http://www.scmexpertonline.com/downloads/SCM_LSMW_StepsOnWeb.doc

http://allsaplinks.com/lsmw.html

http://myweb.dal.ca/hchinni/sap/lsmw_home.htm

[SantoshKallem]

BDC

BDC allows you to perform database updates in the background using standard SAP transactions.

The resultant entries will be as if the user had manually entered the data via SAP. This means

that you do not bypass any of the standard SAP consistency checks, authorisations etc.

There are two main methods of ABAP BDC, these are Call Transaction and Batch Input.

LSMW

http://www.sapgenie.com/saptech/lsmw.htm

http://www.sap-img.com/sap-data-migration.htm

Regards,

santhosh

[Former Member]

Please reward helpfull Answers

The differences between LSMW and BDC are stated as below :

1.lsmw is basically for standard sap application.

BDC is basically for customized applications.

2. In lsmw mapping is take care by sap.

In bdc we have to give mapping concept explicitly.

3. LSMW offers different techniques for migrating data say : Direct input , Batch input recording , BAPI , IDOC.

BDC basically uses recording. There are two methods to implement BDC : (a) Call Trasaction Method

(b) Session Metohd.

4. LSMW is basically designed for Functional consultants who do no coding .

BDC is used by technical consultants , who do coding.

5.In LSMW , Coding cannot be done flexibily as BDC.

On the other hand in BDC ,Coding can be done flexibly to customize applications.

Function module BDC and LSMW are the two data migration techniques (from legacy to SAP) . BDC technique is usually done by ABAPers. It consists of three methods.

1) Call Dialog Method

2) Session Method

3) Call Transaction Method

In the case of Session Method , a BDC Session is created , which has the data and info to run it in batch mode. When the user runs this session, every transactions are run in batch mode and tables are updated.

WHile in call transaction, no session is created. Instead , a report prog is created , which takes input from the file and calls the transaction in Batch mode.

Call dialog method is similar to call transaction, except that updation is done by the calling program itself.This method is obsolete.

Advantages of Batch Input Method are

1)Can process large data volumes

2) data integrity is maintained

Just check these links.

, for reading the value in first list box to populate the values in the secondlist box and so on.

[Former Member]

Hi bhaskar,

1. lsmw - no programming requried,

whereas in call transaction & bdc session,

programming required.

2. in call transaction,

no session concept

(data is updated AS SOON AS we run the prgoram)

where as in lsmw, and session,

SESSION is generated (in both cases)

Only after when we run this session,

does the data get updated.

3. In call transactin program,

we have to handle error list and take action.

whereas in lsmw, & session,

(since session is run)

flexibility is there to check and control errors.

regards,

amit m.

[Former Member]

One more important addition to this

-With LSMW you cannot load Transaction Data(Only master Data can be loaded through LSMW),with BDC's you can do that.

this is a very important diff and a hot favourite Intw question.

_Reward points if usefull

[Former Member]

HI

1) BDC is a mass data transfer technique via screen logic of existing SAP Data entry transactions. It behaves as if you are manually making thousand of entires into sap system as a background job. And that is probably the reason why BAPI's are preffered over BDC's.

2) LSMW is a tool to facilitate DATA migration from other legacy systems ... It contains step by step procedure for data migration.LSMW internally might well be using the following techniqes for data transfer..

1. IDOX

2. Direct Input / BDC

4. BAPI's

3) LSMW mapping is done by SAP while in BDC we have to do it explicitly .

4) Coding can be done flexibly in BDC when compared to LSMW

5) LSMW offers different techinque for migrating data: Direct input ,BAPI,Idoc,Batch input recording. While bdc basically uses recording.

Just look at these links:

Regards,

Gunasree.

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