Building information modeling — BIM — is not a product or proprietary software program. It is an integrated process built on coordinated, reliable information about a project from design through construction and into operations. BIM is not just for architects. While it has its roots in architecture, the principles of BIM apply to everything that is built, including roads and highways, and the benefits of BIM are being experienced by civil engineers in the same way they are enjoyed by architects.
BIM is not just about 3-D (although that is part of it). BIM allows engineers more easily to predict the performance of projects before they are built; respond to design changes faster; optimize designs with analysis, simulation, and visualization; and deliver higher quality construction documentation. Furthermore, it enables extended teams to extract valuable data from the model to facilitate earlier decision making and more economic project delivery.
(source - CE NEWS October 2008)