A method and means, the method includes selecting a plurality of data sources having attributes to be included in a view entity; defining join conditions on the selected plurality of data sources; defining a set of attributes for the view entity by selecting attributes from the attributes of the plurality of data sources; and saving the view entity. The means includes a graphical user interface having a join builder tool to define join conditions on a selected plurality of data sources each including a pre-defined business object data structure having attributes; a view field definition tool to define a set of attributes for the view entity by selecting attributes from the attributes of the plurality of data sources; and a data source tree tool to display all of the attributes of the plurality of data sources.