The existing research of process capability indices of multiple quality characteristics mainly focuses on nonconforming of process output,the concept development of tmivariate process capability indices,quality loss f...The existing research of process capability indices of multiple quality characteristics mainly focuses on nonconforming of process output,the concept development of tmivariate process capability indices,quality loss function and various comprehensive evaluation methods.The multivariate complexity increases the computation difficulty of multivariate process capability indices(MPCI),which makes them hard to be used in practice.In this paper,a new PCA-based MPCI approach is proposed to assess the production capability of the processes that involve multiple product quality characteristics.This approach first transforms the original quality variables into standardized normal variables.MPCI measures are then provided based on the Taam index.Moreover,the statistical properties of these MPCIs,such as confidence intervals and lower confidence bound,are given to let the practitioners understand the capability indices as random variables instead of deterministic variables.A real manufacturing data set and a synthetic data set are used to demonstrate the effectiveness of the proposed method.An implementation procedure is also provided for quality engineers to apply our MPCI approach in their manufacturing processes.The case studies demonstrate the effectiveness and feasibility of this new kind of MPCI,which is easier to be used in production practice.The proposed research provides a novel approach of MPCI calculation.展开更多
Process capability indices have been widely used in the manufacturing industry,providing numerical measures on process precision,process accuracy,and process performance.Capability measures for processes with a single...Process capability indices have been widely used in the manufacturing industry,providing numerical measures on process precision,process accuracy,and process performance.Capability measures for processes with a single characteristic have been investigated extensively.However,capability measures for processes with multiple characteristics are comparatively neglected. In this paper,inspired by the approach and model of process capability index investigated by K.S.Chen et al.(2003) and A.B. Yeh et al.(1998),a note model of multivariate process capability index based on non-conformity is presented.As for this index, the data of each single characteristic don’t require satisfying normal distribution,of which its computing is simple and particioners will not fell too theoretical.At last the application analysis is made.展开更多
For the traditional multi-process capability construction method based on principal component analysis,the process variables are mainly considered,but not the process capability,which leads to the deviation of the con...For the traditional multi-process capability construction method based on principal component analysis,the process variables are mainly considered,but not the process capability,which leads to the deviation of the contribution rate of principal component.In response to the question,this paper first clarifies the problem from two aspects:theoretical analysis and example proof.Secondly,aiming at the rationality of principal components degree,an evaluation method for pre-processing data before constructing MPCI using PCA is proposed.The pre-processing of data is mainly to standardize the specification interval of quality characteristics making the principal components degree more reasonable and optimizes the process capability evaluation method.Finally,the effectiveness and feasibility of the method are proved by an application example.展开更多
Mechanical properties and low cycle fatigue are two factors that must be considered in developin gnew type steel for shock absorption. Process capability and process control are significant factors in achieving the pu...Mechanical properties and low cycle fatigue are two factors that must be considered in developin gnew type steel for shock absorption. Process capability and process control are significant factors in achieving the purpose of research and development programs. Often-used evaluation methods failed to measure processyield and process centering ; so this paper uses Taguchi loss function as basis to establish an evaluation methodand the steps for assessing the quality of mechanical properties and process control of an iron and steel manu-facturer. The establishment of this method can serve the research and development and manufacturing industry and lay a foundation in enhancing its process control ability to select better manufacturing processes that are more reliable than decision making by using the other commonly used methods.展开更多
This paper presents a systematic multivariate process capability index （MPCI） method, which may provide references for assuring and improving process quality levels while achieving an overall evaluation of process q...This paper presents a systematic multivariate process capability index （MPCI） method, which may provide references for assuring and improving process quality levels while achieving an overall evaluation of process quality. The system method includes a spatial MPCI model for multivariate normal distribution data, MPCI model based on factor weight for multivariate no-normal distribution application, and MPCI model based on yield foryield application. At last, examples for calculating MPCI are given, and the experimental results show that this systematic method is effective and practical.展开更多
After analyzing the multivariate Cpm method （Chan et al. 1991）, this paper presents a spatial multivariate process capability index （PCI） method, which can solve a multivariate off-centered case and may provide re...After analyzing the multivariate Cpm method （Chan et al. 1991）, this paper presents a spatial multivariate process capability index （PCI） method, which can solve a multivariate off-centered case and may provide references for assuring and improving process quality level while achieving an overall evaluation of process quality. Examples for calculating multivariate PCI are given and the experimental results show that the systematic method presented is effective and actual.展开更多
针对因工艺参数出现波动导致烟支物理指标呈现离散性问题,重点对制丝与卷接工序中关键参数进行优化。利用L9正交实验的规划方式,针对烘丝温度、压梗厚度、吸阻设定等参数,全面深入地分析其对烟支重量、吸阻及硬度产生影响所遵循的规律...针对因工艺参数出现波动导致烟支物理指标呈现离散性问题,重点对制丝与卷接工序中关键参数进行优化。利用L9正交实验的规划方式,针对烘丝温度、压梗厚度、吸阻设定等参数,全面深入地分析其对烟支重量、吸阻及硬度产生影响所遵循的规律。将响应面法和过程能力指数(Process Capability Index,CPK)相结合构建多目标优化模型,依靠SPC控制图对长期稳定性能进行验证。烘丝温度和烟丝填充值构建二次回归模型,R^(2)数值达到0.92(R^(2)决定系数越接近1,表示模型解释能力越强)。经过对相关参数的优化处理后,烟支重量变异系数(Coefficient of Variation of Cigarette Weight,CV)降低幅度达到40%,CPK值也从1.15提升到了1.53。压梗厚度对吸阻稳定性的影响显著(P<0.01)。研究为卷烟工艺参数的数字化调控管理提供了实践方面的证明根据,有力推动了行业质量管控标准的落地实施与具体应用。展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.70802043,71225006 and 71002105)
文摘The existing research of process capability indices of multiple quality characteristics mainly focuses on nonconforming of process output,the concept development of tmivariate process capability indices,quality loss function and various comprehensive evaluation methods.The multivariate complexity increases the computation difficulty of multivariate process capability indices(MPCI),which makes them hard to be used in practice.In this paper,a new PCA-based MPCI approach is proposed to assess the production capability of the processes that involve multiple product quality characteristics.This approach first transforms the original quality variables into standardized normal variables.MPCI measures are then provided based on the Taam index.Moreover,the statistical properties of these MPCIs,such as confidence intervals and lower confidence bound,are given to let the practitioners understand the capability indices as random variables instead of deterministic variables.A real manufacturing data set and a synthetic data set are used to demonstrate the effectiveness of the proposed method.An implementation procedure is also provided for quality engineers to apply our MPCI approach in their manufacturing processes.The case studies demonstrate the effectiveness and feasibility of this new kind of MPCI,which is easier to be used in production practice.The proposed research provides a novel approach of MPCI calculation.
基金Contract/grant sponsor:China National Key Laboratory for analog IC(51439040103DZ0102)
文摘Process capability indices have been widely used in the manufacturing industry,providing numerical measures on process precision,process accuracy,and process performance.Capability measures for processes with a single characteristic have been investigated extensively.However,capability measures for processes with multiple characteristics are comparatively neglected. In this paper,inspired by the approach and model of process capability index investigated by K.S.Chen et al.(2003) and A.B. Yeh et al.(1998),a note model of multivariate process capability index based on non-conformity is presented.As for this index, the data of each single characteristic don’t require satisfying normal distribution,of which its computing is simple and particioners will not fell too theoretical.At last the application analysis is made.
文摘For the traditional multi-process capability construction method based on principal component analysis,the process variables are mainly considered,but not the process capability,which leads to the deviation of the contribution rate of principal component.In response to the question,this paper first clarifies the problem from two aspects:theoretical analysis and example proof.Secondly,aiming at the rationality of principal components degree,an evaluation method for pre-processing data before constructing MPCI using PCA is proposed.The pre-processing of data is mainly to standardize the specification interval of quality characteristics making the principal components degree more reasonable and optimizes the process capability evaluation method.Finally,the effectiveness and feasibility of the method are proved by an application example.
文摘Mechanical properties and low cycle fatigue are two factors that must be considered in developin gnew type steel for shock absorption. Process capability and process control are significant factors in achieving the purpose of research and development programs. Often-used evaluation methods failed to measure processyield and process centering ; so this paper uses Taguchi loss function as basis to establish an evaluation methodand the steps for assessing the quality of mechanical properties and process control of an iron and steel manu-facturer. The establishment of this method can serve the research and development and manufacturing industry and lay a foundation in enhancing its process control ability to select better manufacturing processes that are more reliable than decision making by using the other commonly used methods.
文摘This paper presents a systematic multivariate process capability index （MPCI） method, which may provide references for assuring and improving process quality levels while achieving an overall evaluation of process quality. The system method includes a spatial MPCI model for multivariate normal distribution data, MPCI model based on factor weight for multivariate no-normal distribution application, and MPCI model based on yield foryield application. At last, examples for calculating MPCI are given, and the experimental results show that this systematic method is effective and practical.
基金Project supported by the Natural Science Foundation of Shaanxi Province(No.2012JQ8048)the Basic Research Foundation of North-western Polytechnical University(No.JC20110232)
文摘After analyzing the multivariate Cpm method （Chan et al. 1991）, this paper presents a spatial multivariate process capability index （PCI） method, which can solve a multivariate off-centered case and may provide references for assuring and improving process quality level while achieving an overall evaluation of process quality. Examples for calculating multivariate PCI are given and the experimental results show that the systematic method presented is effective and actual.
文摘针对因工艺参数出现波动导致烟支物理指标呈现离散性问题,重点对制丝与卷接工序中关键参数进行优化。利用L9正交实验的规划方式,针对烘丝温度、压梗厚度、吸阻设定等参数,全面深入地分析其对烟支重量、吸阻及硬度产生影响所遵循的规律。将响应面法和过程能力指数(Process Capability Index,CPK)相结合构建多目标优化模型,依靠SPC控制图对长期稳定性能进行验证。烘丝温度和烟丝填充值构建二次回归模型,R^(2)数值达到0.92(R^(2)决定系数越接近1,表示模型解释能力越强)。经过对相关参数的优化处理后,烟支重量变异系数(Coefficient of Variation of Cigarette Weight,CV)降低幅度达到40%,CPK值也从1.15提升到了1.53。压梗厚度对吸阻稳定性的影响显著(P<0.01)。研究为卷烟工艺参数的数字化调控管理提供了实践方面的证明根据,有力推动了行业质量管控标准的落地实施与具体应用。
