1. A data migration method for migrating data objects from a source entity to a target entity, wherein the source entity comprises an infrastructure shared between discrete systems, the method comprising: providing an index of the data objects stored on the shared infrastructure and object attributes of the data objects, the index being provided in a normalized format independent of native formats of the discrete systems; selecting which objects to migrate based on at least one object attribute; and optimizing the migration of data from the shared infrastructure to the target entity.