1. An apparatus for collaborative editing of an electronic model of an engineering object, the apparatus comprising: a model datastore configured to store an electronic model, or a copy thereof, for an engineering object that is spatially decomposed into a plurality of editing regions; and a change control module configured to enable a user of a plurality of concurrent users to make changes to an editable feature corresponding to a particular editing region of the plurality of editing regions; and the change control module further configured to block the user of the plurality of concurrent users from making changes to an editable feature corresponding to an editing region assigned to another user of the plurality of concurrent users.