A computational method for performing a data transformation process for use in Engineering Asset Management on an industrial scale is described, The method and associated integration environment includes a transformation engine or module to map model elements and data items from a first information system, for example a procurement and construction database that records the thousands of individual components used to construct an industrial site, to a second information system. Such as an operation and maintenance database. The method uses a model transformation user interface using hierarchically linked layers to allow users to create, view and modify the transformation specification, as well as element terms and element relationships which define a transformation specification, without having to write the underlying code that performs the transformation.