A system maps data within a data source to a target data model, and comprises a computer system including at least one processor. The system determines an identifier for each data object of the data source based on the data within that data object, wherein the identifier indicates for that data object a corresponding concept within a domain ontological representation of a data model of the data source. The determined identifiers for the data objects of the data source are compared to the target data model to determine mappings between the data objects of the data source and the target data model. Data objects from the data source are extracted for the target data model in accordance with the mappings. Present invention embodiments further include a method and computer program product for mapping data within a data source to a target data model.