An entity-based access control model for synchronous collaborative design

Interoperability is very important in a distributed heterogeneous environment. But co-operative actions may cause conflictions, which will lead to different meanings or failure of the operation. Hence, how to maintain the consistency of the design data among the designers with good responsibility is of utmost importance in the synchronous collaborative design system. In the process of real-time coll aborative design, the main design data is the entities which are created and modified in the period of design and red-mark discussion. In view of this point, an entity-based access control mechanism is proposed, and its related authorization methods are discussed. The requirements that may need to be taken into consideration in the synchronous interactions are investigated. Some basic concepts of access control and the data model are specified. And then mechanisms of the confliction avoidance, detection and elimination are studied to guarantee the co-operations to be executed properly and efficiently. Applications of the access control model in the WebCAD, a web-based and real-time environment for the synchronous collaborative design, are also introduced to validate its practicability and effectivity.