SAP LSMW Interview Questions & Answers

Question 1. What Is Lsmw All About?

Answer :

LSMW is a tool provided by SAP in order to upload huge amount of data from legacy file to R/3 system. The Legacy System Migration Workbench (LSMW) is a tool to transfer data from legacy systems (Non SAP System) into an R/3 System (SAP System).

LSMW supports a step-by-step procedure; if one step is executed and saved then next step automatically follows.

Apart from creation of project/ subproject/ object and recording, there are 14 basic steps included in LSMW.

Through LSMW one can create Master data, create transactional data, modify existing master data etc. This tool is very useful when some mass changes are to be carried out and no standard SAP transactions are available for that.

There are few standard objects available in LSMW e.g. material master, vendor master, customer master, purchasing info record, purchase requisitions, purchase orders etc. Using these standard objects one can do mass data upload and mass transactions.

Apart from this LSMW provides another functionality of recording the transaction and then carrying that out many times with large data. Examples are mass deletion of purchase requisitions, mass deletion of planned orders etc.

Question 2. State The Difference Between Lsmw And Bdc?

Answer :

• LSMW is basically designed for functional consultants who do not do much coding but need to explore the functionality while BDC is designed for a technical consultant.
• LSMW offers different technique for migrating data: Direct input, BAPI, I-Doc, Batch input recording while BDC basically uses recording.
• LSMW mapping is done by SAP while in BDC we have to do it explicitly.
• LSMW is basically for standard SAP application while BDC basically for customized application.
• Coding can be done flexibly in BDC when compared to LSMW.

Question 3. When Should We Prefer Using Lsmw Over Other Legacy Data Transfer Methods?

Answer :

• In case if you trust the data in the flat file and know there is not much coding to be done, then we can use LSMW. On the other hand if there is a lot of validations to be done go for BDC.
• Also LSMW can be preferred for uploading Master Data records and standard SAP applications. Since LSMW is a tool and generally it makes use of standard program/objects, the execution would be faster, and less effort is needed to upload master data.

Question 4. What Are The Advantages Of Lsmw?

Answer :

• It's a code free tool (however if required coding can be done) - Therefore it helps functional people to upload data from legacy to SAP system.
• Since it's an uploading tool provided by SAP, it has a structured way of working. You will have to finish every step before starting the next step.
• Since it is integrated in R/3 it is independent of individual platform. The entire project can be downloaded and uploaded in any environment unlike BDC which has to be developed in development server and then transported to Production Server.
• It can be preferred when there is a need to upload large volume of data.
• It is preferred only if there is a requirement for one time transfer of data.

Question 5. What Is The Disadvantages Of Lsmw?

Answer :

LSMW is not suitable for frequent data transfer as there are a number of steps that are to be repeated every time.

Question 6. What Are The Import Methods Available In Lsmw? State The Advantage & Disadvantage Of Each Method?

Answer :

There are four standard import methods available in LSMW.

IDOC's:

• Advantages: Fast to load, easy processing, low programming for standard IDOC’s.
• Disadvantages: Good knowledge of IDOC processing required, time consuming if changes have to be made to a created IDOC.

BAPI’s:

• Advantages: Fast to load, easy processing, logical interface for functional/end user based on the business processes involved.
• Disadvantages: Not always complete with all input fields of a transaction.

STANDARD/DIRECT INPUT:

• Advantages: Well tested method, Fast to load, easy processing.
• Disadvantages: No enjoy transactions, not always complete with all input fields of a transaction.

BATCH INPUT:

• Advantages: Easy modifiable, all fields are available, easy re-processing.
• Disadvantages: Comparatively slow, to use new screens or tabs a new recording has to be created, not easily usable for enjoy transactions, dependent on user settings, difference in foreground and background processing may occur.

Question 7. What Is Data Migration & What Is The Significance Of Data Migration. State The Most Important Data Migration Tools Available In Sap?

Answer :

Data Migration stands for data transfer between two like or alike systems. During SAP R/3 implementation the data needs to be moved from legacy system to the SAP system. Sometimes periodic data transfer between R/3 and other system (interfacing) is also required. Both of the above form a part of data migration.

Significance of data migration are:

• Data migration comes in the end of R/3 implementation.
• To start with Data Migration first configuration should be fully completed
• Data migration is about 20% to 40% of the total implementation expenses.

The tools for data migration are:-

• BDC (Batch Data Communication)
• LSMW (Legacy System Migration Workbench)

Question 8. What Are The Main Functions Of Lsmw?

Answer :

The 3 main functions of the LSMW are:

• Reading the legacy data from one or several files (e.g. spreadsheet tables, sequential files).
• Converting data from its original (legacy system) format to the target (SAP) format
• Importing the data using standard interfaces (Batch Input, Direct Input, BAPI, IDoc) into the database of the R/3 application.

Transaction Code to start the LSM Workbench is LSMW.

Question 9. Can Lsmw Be Used For Handling Multiple Recordings?

Answer :

Generally Multiple Recordings are done for transactions which has multiple access sequences like VK11, TK11, etc. Batch Input Method is capable of handling multiple recording and Batch Input recording is one of the import methods available in LSMW. So yes, LSMW can be used for handling multiple recordings.

Question 10. Can You Carry Out Validations Or Say Can You Write Your Custom Code In Lsmw?

Answer :

Yes, Validations can be carried out in LSMW. Similarly custom code can also be added in LSMW. Validations can be handled in 5th step (Maintain field mapping and conversion rules) of LSMW.

For example, if you are updating Vendor Master, You will need to carry out a validation to check whether vendor is valid or not.

Question 11. Can Data Be Transferred From One R/3 To Another R/3 Via Lsmw?

Answer :

Yes, data can be transferred from one R/3 System to another. Export functionality has to be programmed to achieve the same.

Question 12. Is It Possible To Assign A Transaction Code To A Lsmw Object?

Answer :

Yes, transaction codes can be created from SHD0 for LSMW Objects.

Question 13. What Kind Of Data Can Be Migrated Using The Lsmw? Is It Certain That The Imported Data Will Be Consistent?

Answer :

Wide range of Master Data (e.g. G/L accounts, customer master, vendor master, material master, bills of material) and Transaction Data (e.g. financial documents, sales orders) can be migrated using LSMW.

Yes, the imported data will be consistent because the data is loaded via standard interfaces of the applications which will include all checks that are run for online transactions. 

Question 14. How Many Steps Needs To Be Followed While Using Lsmw For Data Migartion. Also Mention The Steps Sequentially?

Answer :

No. of steps varies for different import methods. Initially there will be 20 steps but after processing step 1 it will reduced to 14 for session method.

Question 15. What Is The Lsm Workbench?

Answer :

The LSM Workbench is an R/3-based tool that supports single or periodic data transfer from your non-SAP system to R/3.

Question 16. What Are The Core Functions Of The Lsm Workbench?

Answer :

Importing legacy data from PC spreadsheet tables or sequential files

Converting data from its original (legacy system) format to the target (R/3) format

Importing the data using the standard interfaces of R/3 (IDoc inbound processing, batch input, direct input)

Question 17. Which Data Can Be Migrated Using The Lsm Workbench?

Answer :

By means of standard transfer programs: a wide range of master data (e.g. G/L accounts, customer master, vendor master, material master, bills of material) and transaction data (e.g. financial documents, sales orders)

By means of recording of transactions: further data objects (if the transaction can be run in batch input mode)

Question 18. Can I Be Certain That The Imported Data Is Consistent?

Answer :

Yes. The data is loaded via the standard interfaces of the applications. This will include all checks that are run for online transactions. Invalid data will be rejected.

Question 19. Can I Be Certain That Conversions Are Carried Out Identically Across The Applications?

Answer :

Yes. The LSM Workbench works on the principle of central (reusable) rules. This approach guarantees that, for example, the material number is converted in the same way wherever the reusable rule is used for conversion.

Question 20. Do I Need An Extensive Knowledge Of Abap To Use The Lsm Workbench?

Answer :

No. The LSM workbench provides the main conversion techniques at the push of a button. For complex conversions, individual ABAP coding can be added.

Question 21. Do I Have To Migrate Table By Table?

Answer :

No. Business objects such as material master, customer master or FI document are migrated

Question 22. Can I Transfer Data That Is On My Pc?

Answer :

Yes. The LSM workbench can read the data directly from your PC. Only when using the periodic interface, the data has to be on a server accessible by R/3

Question 23. Is The Lsm Workbench Part Of The Standard R/3 System?

Answer :

No. The LSM Workbench can be downloaded for free from SAPNET: http://service.sap.com/LSMW

Question 24. Is There An Extra Charge For The Lsm Workbench?

Answer :

No. The LSM Workbench is available free of charge to SAP’s customers and partners

Question 25. Is There An Lsm Training Course?

Answer :

There is no specific training course for LSMW LSMW is part of the 5-day standard training BC420 Workshops at customer site are done at customers charge Examples in the media center can be used for self-study

Question 26. Can I Migrate From R/3 To R/3 Via Lsmw?

Answer :

Yes, but:

Export has to be programmed

Source structures have to be defined

Fields of the source structures can be loaded from the dictionary

Mapping has to be done manually è a lot of fields!! Automatic fieldmapping might be used Import of large data amounts can take a lot of time (most of the time data amount is higher than for Migration from legacy systems) History data can not be build up most of the time

Question 27. Can I Build Periodic Interfaces Using Lsmw?

Answer :

Yes. It is possible to build periodic interfaces using the frame program /SAPDMC/SAP_LSMW_INTERFACE