Development of a Data Warehouse is a major task expected to yield major business benefits regarding the justification of the cost and efforts. However, many ETL projects fail to achieve the required benefits due to improper quality assurance strategy. ETL or Data Migration Testing should ensure the data migrated from heterogeneous sources to the data warehouse occurs with no loss of information/ data, with strict adherence to transfer rules, in compliance with validity checks. ETL Testing should be able to detect early on any problems with the source data if done effectively; any other inconsistencies or ambiguities required to guide data transformation and integration should also be detected during the early stages of ETL Testing. ETL testing should be continuous to ensure the extraction, transformation, and load processes are working as planned and the result is consistent, accurate, and complete. We are the leading Data Migration testing company offering quality testing services to our clients.