1. A method executed in a computer for deriving a transformation for transforming first data conforming with a source data schema to second data conforming to a target data schema, the method comprising: providing an ontology model including classes and properties of classes; providing the source data schema; providing the target data schema, wherein the target data schema is different from the source data schema; identifying a first primary data construct within the source data schema; identifying a first secondary data construct within the first primary data construct; identifying a second primary data construct within the target data schema; identifying a second secondary data construct within the second primary data construct; generating a first mapping for mapping the first primary data construct to a corresponding class of the ontology model; generating a second mapping for mapping the first secondary data construct to a property of the corresponding class of the ontology model; generating a third mapping for mapping the second primary data to a corresponding class of the ontology model; generating a fourth mapping for mapping the second secondary data construct to a property of the corresponding class of the ontology model; and deriving the transformation, wherein the transformation is based on the first mapping, the second mapping, the third mapping, and the fourth mapping.