transfer of data

[Former Member]

how to transfer the data from legacy to r3.

the conversion should take place monthly.

how to validate the data.

[Former Member]

Hi,

You can upload data by using

1. BDC

2.LSMW

U can upload legacy data by using upload function modules like GUI_UPLOAD into internal tables. U can use BDC methods to insert uploaded data into SAP tables.

Regards,

Sankar

[Former Member]

Use BDC and you can schedule the upload by setting this as a background job

Regards,

Reema.

[Former Member]

Hi,

Data can be transferred using BDC, LSMW or BAPIs from legacy. This data is first uploaded in SAP trhough flat files and then used to update data. Data validation can be done before updation or while updating if data is not valid it will give error message and that particualr record will not be updated.

Jogdand M B

[Former Member]

HI Javed,

Analyze the Legacy Data

Defining the data in the legacy system is a huge task. We need to identify the legacy systems that will have the data related to the business processes identified in SAP. The data model of the identified legacy systems needs to be studied to plan for the next stage, that is data mapping.

Map Legacy Data to R/3

Once the data in both the legacy and R/3 System is studied, map the legacy data to SAP fields. “Mapping” assigns specific legacy fields to specific R/3 fields and defines the conversion rules for the data. For example, if the legacy system uses “1” to denote the weight unit “pounds,” and R/3 uses “lb”, legacy field needs to be mapped to the corresponding R/3 field and the value should be converted from “1” to “lb.” There might be some cases where a field is mandatory for the creation of the SAP business object but the corresponding legacy field does not exist. In such cases default values have to be identified for these fields. Hence mapping exercise involves the following

 Map legacy fields to SAP fields

 Define conversion rules.

 Identify default values in SAP.

The mapping and the conversion rules should be documented and signed off by the Legacy system owners and SAP implementation team leads.

Determine the Data Extraction method

Your legacy system may provide a feature, such as report writing, which allows you to retrieve data in the required file format. There might be some existing programs or interfaces, which can be modified for data extraction. There may be some third party tools available to extract data from your legacy system. All these options need to be analysed and the best tool/method should be identified.

Determine the Data Upload method

For uploading data to R/3, following choices exist.

 Manually enter data with online transactions

 Automatic data transfer to SAP

The data transfer method depends on the amount of data that needs to be migrated and the complexity of the business object. For example, for customer names and material master items that are generally huge in number, automatic data transfer is recommended. For payment terms, chart of accounts that are generally small, it is recommended to manually enter in SAP.

Automatic data transfer is recommended whenever there is substantial amount of data because it is easier to deal with upcoming last-minute changes. It also ensures that accurate data is transferred into R/3. SAP provides the following options for data upload.

 Use the SAP standard data transfer programs. Refer to Appendix A for the list of standard programs.

 Write custom batch input programs for data transfer in ABAP/4.

 Loading IDOCs using the IDOC load modules.

 Using BAPI’s and RFCs

The first two options are preferable because, generally data migration involves huge amount of data. Performance of IDOC load modules, RFC and BAPI’s is slow when huge amount of data is involved.

Legacy System Data Migration Work Bench is a tool developed by SAP. This tool is helpful for managing the data migration to SAP.

Determine Data format

After analysing the options available for data extraction and uploading, the two teams should sit together and finalise the extraction and upload format for each business object. The data transfer can be through flat file, tab delimited or a CSV file. This needed to be decided based on the tools and programs available in R/3 and legacy systems. The position and sequence of the fields in the file should also be fixed. This file format has to be documented and signed of by both teams.

Determine Conversion rules

Conversion rules can be incorporated either in the extraction program written in legacy system or in the upload program written in R/3. Separate conversion programs can be written in legacy system or in R/3 if the conversion rules are very complex.

Configuration of the tools/ develop custom programs

In this stage, the legacy development team and R/3 implementation teams have to configure the tool identified based on mapping document. If no tools are available, then custom programs have to be written for extraction, upload and verification. The programs must be flexible enough to incorporate the last minute changes that might arise because of changes to mapping document or SAP customization.

Error Handling

Errors can occur in the programs because of the data type mismatch or any other data inconsistencies. Errors can also occur because of some customisation issues in SAP. Errors must be captured in an error log and provision should be made to reprocess the error records after correcting the data or customisation.

Reporting

The upload programs should give some statistics related to the records uploaded so that they can be compared against what is extracted. These figures can also be verified against verification parameters

Freeze on Customization

Because both the organizational structure and actual customizing influences the data transferred for business objects, finalize or freeze all customisations before the last test run. Customizing changes after the final transfer may result in additional required fields that require preparing and transferring more data. For example, using ten plants instead of one considerably increases the time required to run the final material master transfer because data for each plant has to be transferred. Changing the tax calculations for customers may lead to further required fields in customer master.

Prepare the Legacy Database

It is often easier to delete obsolete data in the legacy system and fix data inconsistencies at data extraction stage rather than during the conversion. Following steps should be followed to prepare the legacy database.

Data Purging

Before transferring data from the legacy system, all the old and obsolete data has to be deleted. For example, to save conversion time and disk space, all one-time customers, vendors, and all unused materials can be deleted.

Data Cleansing

This process corrects data inconsistencies and ensures the integrity of the existing data during the transfer process. Mistakes must be fixed before the transfer.

Reduce Historical Data

With the time and monetary constraints involved and due to the high integration of the R/3 System, it is advisable to transfer as less historical transaction data as possible. The possibility of archiving the historical data can be explored. Or the business can continue using the legacy system for some more time for reporting on the historical data.

Database Space

Before starting the data migration, the disk space requirements in R/3 database needs to be estimated and planned. This could be one of the potential failure points if not planned properly.

Prioritize the business objects

R/3 being a highly integrated system, the business objects need to be transferred in the sequence that will keep the integrity of R/3. For Ex: Material master needs to be transferred before open sales orders.

Hope this is useful for you.reward points if problem solved.

cheers!!

Twinkle

[jyotheswar_p2]

you can transfer the data from a legacy to r3 using following methods in SAP

1.call transaction

2.session method

3.lsmw

4.BAPI

5.direct input method

Depending the no: of records u have to upload and based onthe requirement we have to decide which method to use.

And to run it monthly u have to shcedule a background job in SM36(create),SM37(execute).

hope this will help u.

regards

jyotheswar