Abstract: Quality planning for machining process is an important activity in product quality assurance, whose key issue is to convert part’s quality characteristics to the process quality elements (PQE) and their target levels. A systematic modeling approach is put forward to plan the machining process and determine the optimal level of process quality. A mathematical model was developed to maximize the overall improvement degree of the part’s process quality and subject to three aspecis of constraints : varying ranges of PQEs’ level, interrelationship between PQEs, and quality cost budget to improve PQEs’ level. An illustrative example involved the NC-machining process quality for a thin-walled frame of airship is studied, and the results shows that the proposed optimization model can effectively help process planner or NC programmer determine the optimal level of process quality concerning with resources utilization.

Key words: NC-machining process, Process planning, Process quality, Quality planning