http://scn.sap.com/community/rapid-deployment/blog/2012/05/11/a-better-way-to-migrate-your-sap-data-with-rapid-deployment-solutions

RDS package1) SAP Data Services: Data management platform to support all migration tasks2) SAP Information Steward: Data profiling and assessment as well as data lineage and reconciliation from target to source3) SAP BusinessObjects BI platform: Includes SAP Crystal Dashboard Design (formerly known as Xcelsius Dashboards), SAP BusinessObjects Web Intelligence, and SAP Crystal Reports

Data Services is a well-known and scalable data integration platform for ETL processes (Extract, Transfer, Load). Some of the key features of Data Services include:A single interface to design data structures and build transformation rulesA visualization of source-to-target metadata to analyze data lineage and impactProfile and analyze any source dataDatabase extraction to easily extract legacy systemsEasy mapping (reusable)Reusable and sharable transforms and functions (drag and drop) to minimize own programmingWeb-based administration to manage job operationsOperational dashboards to monitor job execution and trends

Data Services can connect to any source or target system via the adapter framework. While it does have native connectivity to SAP systems, it also has connections to files, ODBC, mainframe, XML, Excel, and many other connectivity options. Architecturally, Data Services resides in the orchestration and integration layer of your existing architecture.Step-by-Step Demo on Using the Migration Content in Data ServicesMigrating Customer Master data to SAP CRM system.

EMIGALL for legacy to sap data migration ,other tools for migration are eCATTLSMW for minor data migration

Three categories of validation are applied to the data. The data is validated to check if mandatory fields are populated; the format and the values of data are acceptable to SAP.

While these seem like standard validations, the framework offers two advantages. First, it is not necessary to load the data into SAP to determine the validity of the data. SAP Best Practices for Data Migration allows data to be validated within its staging area.