1. An article comprising a tangible machine-readable medium operable to cause data processing apparatus to perform operations comprising: receiving a request to initiate an operation, the request containing data characterizing a view, the view characterizing a plurality of hierarchically arranged elements, the elements characterized by the view being associated with elements characterized by two or more business object types; performing the operation on the elements of the two or more business object types; mapping responsive results of the operation to the elements of the view; and generating a message containing the results of the request in a structure compatible with the view.