1. A method for extension of a business application data model stored in one or more non-transitory computer-readable storage media, said method comprising: receiving via a user interface, a selection of an item in a hierarchy of said business application data model; receiving a new attribute of said item; a computer system associating a new attribute identifier of said new attribute with said item; at least one processor in the computer system incorporating into said business application data model a user provided name of the new attribute in association with the new attribute identifier such that said new attribute is included within a searchable ontology of said hierarchy, wherein the user provided name is received in response to a prompt to provide said name; associating a user provided meta attribute with the new attribute identifier, wherein the user provided meta attribute is received in response to another prompt to provide said meta attribute; determining whether a data value received as input for the new attribute of the item is valid, at least by validating the data value in accordance with an inherited meta attribute and by validating the data value in accordance with the user provided meta attribute; wherein the inherited meta attribute for the new attribute identifier is determined automatically from a mandatory meta attribute of a progenitor of said item in said hierarchy; and storing the data value in the business application data model when the data value is determined to be valid.