In order to achieve rapid development process and reduce the time to market, new approaches have been investigated for automotive body assembly design. This research presents a prospective study about using plant digital mock up to support industrialization process and design reviews. The concept of Digital Lot (DLot) is introduced as a design object to validate a layout and assembly processes alternative in a collaborative way. The result is a better synchronization between manufacturing engineers and quick identification of key issues related to the future assembly process configuration.