The data migration is a critical activity for any business. Unless one uses the best practices acceleration it can not be done successfully. 

Also this can help you on how the Agile practices implementation can be useful in several ways in theses projects.

The critical data migration projects can have the below major activities.

During data discovery phase:

1. Identifying the Business scenario based data.
2. Identifying the relevant data schemas.
3. Identifying the tables/queries/SPs, etc. on each of the Data schemas.
4. Planning for each of the Data schemas extraction, Transformation and loading to target applications.
5. Verifying the source and target data flows for business operation continuity.

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