Design versions in a distributed CAD environment

A mechanism is presented for dealing with evolving design objects in a distributed design environment. A design activity is decomposed into subprojects that can in turn be divided into smaller databases. Designers working on similar projects are governed by some simple rules that are based on this hierarchy, such as version visibility, mutability, write access, etc. Concurrency control problems on a design version are deassociated from the design activity; designers perform their updates on a new version, which is a copy of the original one, in their own private database. The authors discuss system architecture issues based on the generally accepted server/client model.<>