To design a reasonable dimensional tolerance of a transmission shaft, the higher product quality while lower manufacturing cost must be considered. This paper provides a mathematical model and a flowchart which elucidates the relationship between process capability index (PCI), reliability, tolerance and manufacturing cost, considering the characteristics of the shaft diameter, the material and manufacturing process. A 10.904% cost reduction under certain PCI range of a real case shows the effectiveness of the model and flowchart, thus it can be applied to those technical area when optimizing product design.

中文翻译：

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基于最小成本和可靠性目标的汽车传动轴公差分析

设计合理的传动轴尺寸公差，必须考虑较高的产品质量和较低的制造成本。考虑到轴直径、材料和制造工艺的特点，本文提供了一个数学模型和流程图，阐明了工艺能力指数（PCI）、可靠性、公差和制造成本之间的关系。实际案例在一定PCI范围下成本降低了10.904%，说明了模型和流程图的有效性，因此可以应用于优化产品设计时的技术领域。