Legacy Systems Migration WorkbenchSummary of Objectives
Reviewed the LSMW ArchitectureInvestigated the steps to set-up a
LSMW conversionExecuted a LSMW-developed Read, Convert & Data
Load
R/3 SystemJanuary 2000
Interfacing Techniques in R/3Legacy Systems Migration
Workbench
This presentation will introduce the attendees to the world of
the SAP R/3 Utility - The Legacy System Migration Workbench
SAP offers a multitude of interfacing options. With continuing
R&D of the application, the number of available ways of getting
external data into SAP is constantly expanding.
The Data Methods shown here have been separated into three main
avenues:Synchronous - commonly used in query tasks, these methods
allow for real-time telephone-style communicationAsynchronous -
commonly used in update tasks, one way e-mail style communication
either to or from SAPOne-Way - tools that allow for a
single-direction update into SAP. Used primarily for data loads
Legacy Systems Migration WorkbenchSAP-development environment to
make getting Legacy Information into SAP simpler. In particular,
the workbench offers a tool to translate legacy data structures
into a format that SAP understands.While SAP requires data in
particular flat-file format in order for it to be processed, LSMW
provides a means to do this.LSMW will generate code to Read in the
information and Convert the information into SAP-ready form. This
SAP-ready structure can be in any of the above listed formats. The
most commonly used one is the Standard Data Transfer structure.
The LSM Workbench is an add-on supplied by SAP at no additional
charge. It was developed on a customer implementation and then made
into a generic, generally available utility.The LSM Workbench
provides an increasingly strong alternative to the plethora of
third-party data conversion products available.The LSM Workbench is
designed around a process-oriented User Interface. Each activity is
identified. This is customizable by the user.The SAP Target can
come in multiple flavors - these are all supported by the LSM
Workbench as standard.
The Source File format can be defined using the LSM Workbench
and its tools.In this exercise the project is created.
Subsequently, data source and target structures are defined.Once
the high-level structures are defined the detailed field-level
mapping can be established. Two commonly used examples are shown
here:Fixed Values - i.e.. Non-changing parameters such as a
transaction code.Source file valuesIn addition, a third commonly
performed mapping would be rules-based. This involves manipulation
of the data as it gets passed into the target format. The rules are
developed using ABAP.
In this exercise field-mappings and fixed values are
established.The above chart shows the files that will be used /
updated in the LSM Conversion ProcessIn this exercise file names
are associated with the source file, the loaded data file and the
converted data file.The above chart illustrates the conversion
process. Note that the conversion process is defined into three
stages:Loading of the source data into an Application Server
directory.Conversion of the loaded data.Loading of the converted
data into SAP via the selected option.
Note that this approach allows selective loading / converting of
the data as and when required.
In this exercise the data is run through the LSM Workbench
generated files, resulting in an SAP-ready file format. This can
then be used via the standard approach.
Communication is done via a specially formatted flat file.
Formatting of this file can be done using either ABAP on a simple
text file, or via an external conversion routine. The result is
then placed on the application server (usually via FTP) and a SAP
program is executed.
This is one option for the LSM Workbench - the data can also be
passed for use in a BAPI, IDOC, or custom-created BDC session.
The options discussed in these slides give a good indication of
the development of SAP tools and how they have matured with the
product.
The Legacy Migration Workbench was developed to address a need
created by the Data Transfer Workbench. From 4.6 these are being
consolidated into a single transaction-offering. Of a sort
