The process known as data migration is, in its most general meaning, the transfer of data between formats, types of storage and computer systems. Usually it is performed when a new system is adopted (through change, upgrade or purchase) and the data in both systems need to map to each other without difficulties. As the very process of data migration requires a considerable amount of time and labor, in most cases it is done automatically, although manual methods are also frequently used.
It is common that data cleansing is performed during the procedure of data migration for the purpose of data quality improvement and matching the requirements of the new system.
There are two variables to be taken into consideration when deciding on data migration - data volume and data value. Although they are both important for the process, it is the data volume that is the most crucial criterion once the decision of data migration has been made.
Before the proper migration begins, there is a set of analyses to be performed: the analysis and definition of source structure the analysis and definition of target structure mapping between source and target structure definition of the migration method.