Difference between BDC & LSMW
LSMW offers different technique for migrating data: Direct input, BAPI, Idoc, Batch input recording. While BDC basically uses batch input sessions and CALL TRANSACTION method.
Limit on number of records which can be uploaded in one session of BDC (999 records). No such limit in LSMW.
LSMW is more to do with configuration while BDC involves programming.
LSMW
The LSM Workbench is a tool that supports data transfer from non-SAP systems to R/3. The main functions of the LSM Workbench are:
- Import data (legacy data in spreadsheet tables and/or sequential files)
- Convert data (from source format to target format)
- Import data (into the database of the R/3 application)
Principles of LSM Workbench
Basic Principles of LSM workbench:-
Most of the functions should reside in R/3. No collection of individual programs on different platforms.
The quality and consistence of the data imported into R/3 should be more important than speed and performance of data migration.
Existing knowledge and coding should be used.
The developed ”mapping" and rules should be reusable and thus be used repeatedly in projects.
Features:-
Integrated in R/3 and thus independent of individual platforms
The import technique to be used in an individual case, depends on the business object as well as on the availability of standard input programs
Data consistency due to standard import techniques:
Batch input
Direct input
BAPIs (Business Application Programming Interfaces)
IDocs (Intermediate Documents)
Structured way of working, because you have to finish every step before starting the next step
Pre-requisites for LSMW
Make sure that SAP customizing is finished.
Run the relevant transaction in the SAP system manually with test data from the legacy system and see which fields must be filled. There may be required fields that do not correspond to data fields in the legacy system. In such a case, one should better assign a fixed value or establish an optional field for data transfer.
Map the fields in advance in written form: Assign the source fields to the target fields.
Determine the form in which non-SAP data will be transferred into the SAP system (e.g. via "Move" or according to a rule).
Preferred methods of input are described in order of preference:
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
2. 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
3. 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.
4. 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, dependant on user settings, difference in foreground and background processing may occur.
Reward if useful.
Bluesky
