Real-time collaborative design for cloud computing CAD system

A new real-time collaborative design technology of cloud computing CAD system is introduced in this paper. By using the cloud computing CAD system with the new technology, multi-designer can do their design in one document at the same time, and exchange design data conveniently. A new document structure used in cloud computing CAD system is given. This is a multi-layer structure, and can be expanded dynamically with the increase of users. The user data permissions between these layers are defined. A CAD system architecture which is built base on the multi-layer document structure is discussed. The system´s work flow and the document structure are also shown in the end through an example.