Abstract: Process decision is the key point to the development of CAPP system. We divided the process decision into three separate sub-tasks: Generation of feature machining chain; process operations sequencing; and process steps sequencing. Each sub-task focuses on resolving only a main problem and neglects other secondary factors. Further more, different strategy adaptive to each kind of sub-task is worked out individually, thus effectively reducing the scale of process sequencing and complexity of the sequencing algorithm. Key techniques of solution are implemented in a RJ-CAPP system.