Failure mode and effects analysis （FMEA） offers a quick and easy way for identifying ranking-order for all failure modes in a system or a product. In FMEA the ranking methods is so called risk priority number （RPN...Failure mode and effects analysis （FMEA） offers a quick and easy way for identifying ranking-order for all failure modes in a system or a product. In FMEA the ranking methods is so called risk priority number （RPN）, which is a mathematical product of severity （S）, occurrence （0）, and detection （D）. One of major disadvantages of this ranking-order is that the failure mode with different combination of SODs may generate same RPN resulting in difficult decision-making. Another shortfall of FMEA is lacking of discerning contribution factors, which lead to insufficient information about scaling of improving effort. Through data envelopment analysis （DEA） technique and its extension, the proposed approach evolves the current rankings for failure modes by exclusively investigating SOD in lieu of RPN and to furnish with improving sca.les for SOD. The purpose of present study is to propose a state-of-the-art new approach to enhance assessment capabilities of failure mode and effects analysis （FMEA）. The paper proposes a state-of-the-art new approach, robust, structured and useful in practice, for failure analysis.展开更多
Reliability allocation of computerized numerical controlled（CNC）lathes is very important in industry.Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate compon...Reliability allocation of computerized numerical controlled（CNC）lathes is very important in industry.Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components,which is not applicable in some conditions.Aiming at solving the problem of CNC lathes reliability allocating,a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis（FMEA）is presented.Firstly,conventional reliability allocation methods are introduced.Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated.Subsequently,a cubic transformed function is established in order to overcome these limitations.Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence.Designers can choose appropriate transform amplitudes according to their requirements.Finally,a CNC lathe and a spindle system are used as an example to verify the new allocation method.Seven criteria are considered to compare the results of the new method with traditional methods.The allocation results indicate that the new method is more flexible than traditional methods.By employing the new cubic transformed function,the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.展开更多
To explore the influencing factors of survival time of patients with heart failure, a total of 1789 patients with heart failure were collected from Shanghai Shuguang Hospital. The Cox proportional hazards model and th...To explore the influencing factors of survival time of patients with heart failure, a total of 1789 patients with heart failure were collected from Shanghai Shuguang Hospital. The Cox proportional hazards model and the mixed effects Cox model were used to analyze the factors on survival time of patients. The results of Cox proportional hazards model showed that age (RR = 1.32), hypertension (RR = 0.67), ARB (RR = 0.55), diuretic (RR = 1.48) and antiplatelet (RR = 0.53) have significant impacts on the survival time of patients. The results of mixed effects Cox model showed that age (RR = 1.16), hypertension (RR = 0.61), lung infection (RR = 1.43), ARB (RR = 0.64), β-blockers (RR = 0.77) and antiplatelet (RR = 0.69) have a significant impact on the survival time of patients. The results are consistent with the covariates age, hypertension, ARB and antiplatelet but inconsistent with the covariates lung infection and β-blockers.展开更多
A new method of system failure analysis was proposed. First, considering the relationships between the failure subsystems,the decision making trial and evaluation laboratory(DEMATEL) method was used to calculate the d...A new method of system failure analysis was proposed. First, considering the relationships between the failure subsystems,the decision making trial and evaluation laboratory(DEMATEL) method was used to calculate the degree of correlation between the failure subsystems, analyze the combined effect of related failures, and obtain the degree of correlation by using the directed graph and matrix operations. Then, the interpretative structural modeling(ISM) method was combined to intuitively show the logical relationship of many failure subsystems and their influences on each other by using multilevel hierarchical structure model and obtaining the critical subsystems. Finally, failure mode effects and criticality analysis(FMECA) was used to perform a qualitative hazard analysis of critical subsystems, determine the critical failure mode, and clarify the direction of reliability improvement.Through an example, the result demonstrates that the proposed method can be efficiently applied to system failure analysis problems.展开更多
The failure modes and effects analysis （FMEA） is widely applied in manufacturing industries in various phases of the product life cycle to evaluate the system, its design and processes for failures that can occur. T...The failure modes and effects analysis （FMEA） is widely applied in manufacturing industries in various phases of the product life cycle to evaluate the system, its design and processes for failures that can occur. The FMEA team often demonstrates different opinions and these different types of opinions are very difficult to incorporate into the FMEA by the traditional risk priority number model. In this paper, for each of the Occurrence, Severity and Detectivity parameters a fuzzy set is defined and the opinion of each FMEA team members is considered. These opinions are considered simultaneously with weights that are given to each individual based on their skills and experience levels. In addition, the opinion of the costumer is considered for each of the FMEA parameters. Then, the Risk Priority Numbers （RPN） is calculated using a Multi Input Single Output （MISO） fuzzy expert system. The proposed model is applied for prioritizing the failures of Peugeot 206 Engine assembly line in IKCo （Iran Khodro Company）.展开更多
针对传统故障模式和影响分析(failure mode and effect analysis,FMEA)方法存在评价使用精确数量化造成专家风险评估信息的丢失、忽略风险指标之间的相对重要性以及由于专家有限理性导致的评价固有的随机性等问题,利用区间值直觉模糊集...针对传统故障模式和影响分析(failure mode and effect analysis,FMEA)方法存在评价使用精确数量化造成专家风险评估信息的丢失、忽略风险指标之间的相对重要性以及由于专家有限理性导致的评价固有的随机性等问题,利用区间值直觉模糊集和云模型构建了一种改进的FMEA风险评估方法。首先,引入区间值直觉模糊集(IVIFS)来描述专家评价信息的复杂性和不确定性,通过运用区间值直觉模糊熵,计算专家权重和风险因子的权重;其次,采用云模型的方法,通过比较各支持云模型和反对云模型与正、负理想云模型的正、负相似度,获得故障模式评价值的综合相似度,通过对综合相似度大小排序得到各故障模式风险排序;最后,以自动扶梯的梯级、踏板和胶带风险评估为例进行分析,验证该评估方法的实用性和可行性。展开更多
提出一种改进失效模式与影响分析(Failure Mode and Effect Analysis,FMEA)模型用于智能制造系统可靠性风险评估。首先基于文献法、专家访谈和鱼骨图分析法,从人、机、料、法、环(Human-Machine-Material-Method-Environment,4M1E)五个...提出一种改进失效模式与影响分析(Failure Mode and Effect Analysis,FMEA)模型用于智能制造系统可靠性风险评估。首先基于文献法、专家访谈和鱼骨图分析法,从人、机、料、法、环(Human-Machine-Material-Method-Environment,4M1E)五个方面识别智能制造运行过程中的潜在失效模式;其次使用三角模糊数获取专家对失效模式的风险评估信息,风险因子权重由结构熵权法计算确定;最后运用模糊C均值(Fuzzy C-Means,FCM)算法划分失效模式的风险等级。此外,为了检验结果的有效性和可靠性,采用对比分析和蒙特卡洛仿真进行验证。展开更多
目的观察失效模式与效应分析(Failure mode and effect analysis,FMEA)模式下构建急诊危重症患者临床护理路径管理的效果。方法淮安市第一人民医院于2019年1月开始施行FMEA模式下构建急诊危重症患者临床护理路径管理(简称FMEA临床路径)...目的观察失效模式与效应分析(Failure mode and effect analysis,FMEA)模式下构建急诊危重症患者临床护理路径管理的效果。方法淮安市第一人民医院于2019年1月开始施行FMEA模式下构建急诊危重症患者临床护理路径管理(简称FMEA临床路径),利用回顾性分析方法收集2018年1月-2018年12月就诊本院的急诊危重症患者82例(对照组),利用倾向性评分匹配法在2019年2月-2020年6月就诊患者中选择与对照组具有相同性别、年龄、急性生理和慢性健康评分(APACHEⅡ)、发病至入院时间、疾病类别的急诊危重症患者82例(观察组),两组匹配比例为1∶1,用于确定FMEA临床路径前后患者的抢救室滞留时间、抢救时间、住院时间、危重症交接时间、抢救成功率、转运相关不良事件发生情况、并发症控制情况差异。结果观察组患者抢救室滞留时间、抢救时间、危重症交接时间,转运期间血压下降、呼吸骤停、心搏骤停、管道脱落/堵塞、药品物品不齐、交接不清、转运延迟以及压疮、下肢深静脉血栓、跌倒发生率及并发症总发生率均低于对照组(P<0.05);观察组患者抢救成功率为95.12%(78/82),高于对照组抢救成功率(P<0.05);观察组健康教育完成度评分高于对照组,差异有统计学意义(P<0.05)。结论FMEA模式下构建急诊危重症患者临床护理路径管理方案能够有效降低抢救室滞留时间、抢救时间、危重症交接时间、转运期间风险事件及抢救后压疮、下肢深静脉血栓、跌倒并发症风险,有效提升抢救成功率,有助于提升护理人员健康教育完成度。展开更多
文摘Failure mode and effects analysis （FMEA） offers a quick and easy way for identifying ranking-order for all failure modes in a system or a product. In FMEA the ranking methods is so called risk priority number （RPN）, which is a mathematical product of severity （S）, occurrence （0）, and detection （D）. One of major disadvantages of this ranking-order is that the failure mode with different combination of SODs may generate same RPN resulting in difficult decision-making. Another shortfall of FMEA is lacking of discerning contribution factors, which lead to insufficient information about scaling of improving effort. Through data envelopment analysis （DEA） technique and its extension, the proposed approach evolves the current rankings for failure modes by exclusively investigating SOD in lieu of RPN and to furnish with improving sca.les for SOD. The purpose of present study is to propose a state-of-the-art new approach to enhance assessment capabilities of failure mode and effects analysis （FMEA）. The paper proposes a state-of-the-art new approach, robust, structured and useful in practice, for failure analysis.
基金Supported by National Natural Science Foundation of China(Grant Nos.51135003,51205050,U1234208)Key National Science & Technology Special Project on"High-Grade CNC Machine Tools and Basic Manufacturing Equipments"(Grant No.2013ZX04011011)+1 种基金Research Fund for the Doctoral Program of Higher Education of China(Grant No.20110042120020)Fundamental Research Funds for the Central
文摘Reliability allocation of computerized numerical controlled（CNC）lathes is very important in industry.Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components,which is not applicable in some conditions.Aiming at solving the problem of CNC lathes reliability allocating,a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis（FMEA）is presented.Firstly,conventional reliability allocation methods are introduced.Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated.Subsequently,a cubic transformed function is established in order to overcome these limitations.Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence.Designers can choose appropriate transform amplitudes according to their requirements.Finally,a CNC lathe and a spindle system are used as an example to verify the new allocation method.Seven criteria are considered to compare the results of the new method with traditional methods.The allocation results indicate that the new method is more flexible than traditional methods.By employing the new cubic transformed function,the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.
文摘To explore the influencing factors of survival time of patients with heart failure, a total of 1789 patients with heart failure were collected from Shanghai Shuguang Hospital. The Cox proportional hazards model and the mixed effects Cox model were used to analyze the factors on survival time of patients. The results of Cox proportional hazards model showed that age (RR = 1.32), hypertension (RR = 0.67), ARB (RR = 0.55), diuretic (RR = 1.48) and antiplatelet (RR = 0.53) have significant impacts on the survival time of patients. The results of mixed effects Cox model showed that age (RR = 1.16), hypertension (RR = 0.61), lung infection (RR = 1.43), ARB (RR = 0.64), β-blockers (RR = 0.77) and antiplatelet (RR = 0.69) have a significant impact on the survival time of patients. The results are consistent with the covariates age, hypertension, ARB and antiplatelet but inconsistent with the covariates lung infection and β-blockers.
基金Project(51275205)supported by the National Natural Science Foundation of China
文摘A new method of system failure analysis was proposed. First, considering the relationships between the failure subsystems,the decision making trial and evaluation laboratory(DEMATEL) method was used to calculate the degree of correlation between the failure subsystems, analyze the combined effect of related failures, and obtain the degree of correlation by using the directed graph and matrix operations. Then, the interpretative structural modeling(ISM) method was combined to intuitively show the logical relationship of many failure subsystems and their influences on each other by using multilevel hierarchical structure model and obtaining the critical subsystems. Finally, failure mode effects and criticality analysis(FMECA) was used to perform a qualitative hazard analysis of critical subsystems, determine the critical failure mode, and clarify the direction of reliability improvement.Through an example, the result demonstrates that the proposed method can be efficiently applied to system failure analysis problems.
文摘The failure modes and effects analysis （FMEA） is widely applied in manufacturing industries in various phases of the product life cycle to evaluate the system, its design and processes for failures that can occur. The FMEA team often demonstrates different opinions and these different types of opinions are very difficult to incorporate into the FMEA by the traditional risk priority number model. In this paper, for each of the Occurrence, Severity and Detectivity parameters a fuzzy set is defined and the opinion of each FMEA team members is considered. These opinions are considered simultaneously with weights that are given to each individual based on their skills and experience levels. In addition, the opinion of the costumer is considered for each of the FMEA parameters. Then, the Risk Priority Numbers （RPN） is calculated using a Multi Input Single Output （MISO） fuzzy expert system. The proposed model is applied for prioritizing the failures of Peugeot 206 Engine assembly line in IKCo （Iran Khodro Company）.
文摘针对传统故障模式和影响分析(failure mode and effect analysis,FMEA)方法存在评价使用精确数量化造成专家风险评估信息的丢失、忽略风险指标之间的相对重要性以及由于专家有限理性导致的评价固有的随机性等问题,利用区间值直觉模糊集和云模型构建了一种改进的FMEA风险评估方法。首先,引入区间值直觉模糊集(IVIFS)来描述专家评价信息的复杂性和不确定性,通过运用区间值直觉模糊熵,计算专家权重和风险因子的权重;其次,采用云模型的方法,通过比较各支持云模型和反对云模型与正、负理想云模型的正、负相似度,获得故障模式评价值的综合相似度,通过对综合相似度大小排序得到各故障模式风险排序;最后,以自动扶梯的梯级、踏板和胶带风险评估为例进行分析,验证该评估方法的实用性和可行性。
文摘目的观察失效模式与效应分析(Failure mode and effect analysis,FMEA)模式下构建急诊危重症患者临床护理路径管理的效果。方法淮安市第一人民医院于2019年1月开始施行FMEA模式下构建急诊危重症患者临床护理路径管理(简称FMEA临床路径),利用回顾性分析方法收集2018年1月-2018年12月就诊本院的急诊危重症患者82例(对照组),利用倾向性评分匹配法在2019年2月-2020年6月就诊患者中选择与对照组具有相同性别、年龄、急性生理和慢性健康评分(APACHEⅡ)、发病至入院时间、疾病类别的急诊危重症患者82例(观察组),两组匹配比例为1∶1,用于确定FMEA临床路径前后患者的抢救室滞留时间、抢救时间、住院时间、危重症交接时间、抢救成功率、转运相关不良事件发生情况、并发症控制情况差异。结果观察组患者抢救室滞留时间、抢救时间、危重症交接时间,转运期间血压下降、呼吸骤停、心搏骤停、管道脱落/堵塞、药品物品不齐、交接不清、转运延迟以及压疮、下肢深静脉血栓、跌倒发生率及并发症总发生率均低于对照组(P<0.05);观察组患者抢救成功率为95.12%(78/82),高于对照组抢救成功率(P<0.05);观察组健康教育完成度评分高于对照组,差异有统计学意义(P<0.05)。结论FMEA模式下构建急诊危重症患者临床护理路径管理方案能够有效降低抢救室滞留时间、抢救时间、危重症交接时间、转运期间风险事件及抢救后压疮、下肢深静脉血栓、跌倒并发症风险,有效提升抢救成功率,有助于提升护理人员健康教育完成度。
