Abstract: The design principles and functions of GNCPPPS are dealt with, which is an intelligent Graphics NC Programming and Process Planning system, and an intelligent model for BNCPPPS is developed. The plan design and conceptual modelling are proposed to describe the behaviour and knowledge for GNCPPPS. The Machined Feature Unit (MFU) is proposed. It is considered that the part to be machined is composed of a set of MFUs, which are automatically recognized from 3D solid model, and carry not only the geometric and topologic information, but also the information about how to machine them and to generate tool paths. The concept models representing machine tool base, cutting too! base, machining parameter base are studied in this paper. The facilitating factors for selecting processes, machine tools, cutting tools and machining parameters are analyzed, and reasoning models for selecting them are created.

Key words: AI system, process planning, graphics NC programming, machine feature unit