Abstract: In order to solve the problem of information inconsistencies in 3D machining process planning,a 3D process design method of machining was proposed based on Model-Based Definition (MBD).The 3D machining process planning frame based on MBD processing element were established after concept of MBD processing element was given.Processing element generating method and process decision was researched.Boolean operators and replication technology are used process model to found the process model by MBD processing element.A machining process design system was developed based MBD processing element.The effectiveness and correctness of proposed method was verified by the example of an process design for boxes parts.

Key words: Model-Based Definition (MBD), MBD processing element, process model, Boolean operators