An computer-aided automatic design processing system for designing processes for the machining of parts includes a process design processing section for deciding a machining device, a machining mode, and a machining reference surface based on a parts model of parts to be machined and a data base for production, a forming and verifying section for forming and verifying a process plan based on the output of the process design section processing section, and a fixture processing section. The system is capable of performing the computer processing of a process plan and a fixture plan.