Abstract: In order to improve the machining accuracy, the accuracy design of quality characteristics (QCs) for numerical control machine is analyzed and evaluated. The accuracy design of numerical control machine is a complex engineering optimization problem with requirements of multiple factors and QCs, and all QCs need to meet specific technical standards. According to the requirement of process accuracy for numerical control machine, the quality factors (QFs) which have impact on accuracy design QCs are identified. Therefore, a reverse mapping model based on rough set (RS) and house of quality (HoQ) in quality function deployment (QFD) is also proposed. RS theory is first applied to simplify and extract the QFs of the machining quality. A novel concept known as approximate accuracy rough number is used to determine the final importance weights of the QFs. Furthermore, a reverse mapping model is designed to translate the main QFs into accuracy design QCs and confirm the importance degree of accuracy design QCs, which would help product designers achieve the design goals in product development. The applicability of the proposed reverse mapping model is demonstrated by an illustrative example of machining center.

Key words: Accuracy design, Numerical control machine, Quality characteristics, Quality function deployment, Rough set