Reliability is reflected in product during manufacturing. However, due to uncontrollable factors during production, product reliability may degrade substantially after manufacturing. Thus, root cause analysis is important in identifying vulnerable parameters to prevent the product reliability degradation in manufacturing. Therefore, a novel root cause identification approach based on quality function deployment (QFD) and extended risk priority number (RPN) is proposed to prevent the degradation of product manufacturing reliability. First, the connotation of product manufacturing reliability and its degradation mechanism are expounded. Second, the associated tree of the root cause of product manufacturing reliability degradation is established using the waterfall decomposition of QFD. Third, the classic RPN is extended to focus on importance to reliability characteristics, probability, and un-detectability. Furthermore, fuzzy linguistic is adopted and the integrated RPN is calculated to determine the risk of root causes. Therefore, a risk-oriented root cause identification technique of product manufacturing reliability degradation is proposed using RPN. Finally, a root cause identification of an engine component is presented to verify the effectiveness of this method. Results show that the proposed approach can identify the root cause objectively and provide reference for reliability control during production.

可靠性体现在产品制造过程中。然而，由于生产过程中的不可控因素，产品制造后的可靠性可能会大幅下降。因此，根本原因分析对于识别易受攻击的参数以防止制造过程中的产品可靠性下降非常重要。因此，提出了一种基于质量功能部署（QFD）和扩展风险优先级数（RPN）的新型根本原因识别方法，以防止产品制造可靠性的下降。首先，阐述了产品制造可靠性的内涵及其退化机理。其次，利用QFD的瀑布分解建立了产品制造可靠性下降根本原因的关联树。第三，经典的 RPN 被扩展到关注可靠性特性、概率和不可检测性的重要性。此外，采用模糊语言并计算综合 RPN 来确定根本原因的风险。因此，提出了一种基于风险的RPN产品制造可靠性劣化根本原因识别技术。最后，提出了发动机部件的根本原因识别，以验证该方法的有效性。结果表明，所提出的方法可以客观地找出根本原因，为生产过程中的可靠性控制提供参考。提出了一种基于RPN的产品制造可靠性退化风险导向的根本原因识别技术。最后，提出了发动机部件的根本原因识别，以验证该方法的有效性。结果表明，所提出的方法可以客观地找出根本原因，为生产过程中的可靠性控制提供参考。提出了一种基于RPN的产品制造可靠性退化风险导向的根本原因识别技术。最后，提出了发动机部件的根本原因识别，以验证该方法的有效性。结果表明，所提出的方法可以客观地找出根本原因，为生产过程中的可靠性控制提供参考。