scholarly journals Risk Evaluation in Failure Mode and Effects Analysis Based on D Numbers Theory

Author(s):  
Baoyu Liu ◽  
Yong Deng

Failure mode and effects analysis (FMEA) is a useful technology for identifying the potential faults or errors in system, and simultaneously preventing them from occurring. In FMEA, risk evaluation is a vital procedure. Many methods are proposed to address this issue but they have some deficiencies, such as the complex calculation and two adjacent evaluation ratings being considered to be mutually exclusive. Aiming at these problems, in this paper, A novel method to risk evaluation based on D numbers theory is proposed. In the proposed method, for one thing, the assessments of each failure mode are aggregated through D numbers theory. For another, the combination usage of risk priority number (RPN) and the risk coefficient newly defined not only achieve less computation complexity compared with other methods, but also overcome the shortcomings of classical RPN. Furthermore, a numerical example is illustrated to demonstrate the effectiveness and superiority of the proposed method.

2018 ◽  
Vol 13 (2) ◽  
pp. 205-220 ◽  
Author(s):  
Baoyu Liu ◽  
Yong Hu ◽  
Yong Deng

Failure mode and effects analysis (FMEA) is extensively applied to process potential faults in systems, designs, and products. Nevertheless, traditional FMEA, classical risk priority number (RPN), acquired by multiplying the ratings of occurrence, detection, and severity, risk assessment, is not effective to process the uncertainty in FMEA. Many methods have been proposed to solve the issue but deficiencies exist, such as huge computing quality and the mutual exclusivity of propositions. In fact, because of the subjectivity of experts, the boundary of two adjacent evaluation ratings is fuzzy so that the propositions are not mutually exclusive. To address the issues, in this paper, a new method to evaluate risk in FMEA based on D numbers and evidential downscaling method, named as D numbers downscaling method, is proposed. In the proposed method, D numbers based on the data are constructed to process uncertain information and aggregate the assessments of risk factors, for they permit propositions to be not exclusive mutually. Evidential downscaling method decreases the number of ratings from 10 to 3, and the frame of discernment from 2^{10} to 2^3 , which greatly reduce the computational complexity. Besides, a numerical example is illustrated to validate the high efficiency and feasibility of the proposed method.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ammar Chakhrit ◽  
Mohammed Chennoufi

Purpose This paper aims to enable the analysts of reliability and safety system to assess the criticality and prioritize failure modes perfectly to prefer actions for controlling the risks of undesirable scenarios. Design/methodology/approach To resolve the challenge of uncertainty and ambiguous related to the parameters, frequency, non-detection and severity considered in the traditional approach failure mode effect and criticality analysis (FMECA) for risk evaluation, the authors used fuzzy logic where these parameters are shown as members of a fuzzy set, which fuzzified by using appropriate membership functions. The adaptive neuro-fuzzy inference system process is suggested as a dynamic, intelligently chosen model to ameliorate and validate the results obtained by the fuzzy inference system and effectively predict the criticality evaluation of failure modes. A new hybrid model is proposed that combines the grey relational approach and fuzzy analytic hierarchy process to improve the exploitation of the FMECA conventional method. Findings This research project aims to reflect the real case study of the gas turbine system. Using this analysis allows evaluating the criticality effectively and provides an alternate prioritizing to that obtained by the conventional method. The obtained results show that the integration of two multi-criteria decision methods and incorporating their results enable to instill confidence in decision-makers regarding the criticality prioritizations of failure modes and the shortcoming concerning the lack of established rules of inference system which necessitate a lot of experience and shows the weightage or importance to the three parameters severity, detection and frequency, which are considered to have equal importance in the traditional method. Originality/value This paper is providing encouraging results regarding the risk evaluation and prioritizing failures mode and decision-makers guidance to refine the relevance of decision-making to reduce the probability of occurrence and the severity of the undesirable scenarios with handling different forms of ambiguity, uncertainty and divergent judgments of experts.


Author(s):  
Ю.І. Сеник

У роботі розглянуто застосування модифікованого до системи ощадливого виробництва методу оцінки ризиків FMEA для виробничих лабораторій молокопереробних підприємств. Описано алгоритм реалізації failure mode and effect analysis та вказано основні принципи розрахунку S (значимість потенційних збоїв у роботі), O (ймовірність виникнення збою у роботі), D (ймовірність виявлення збою) та RPN (risk priority number). Розглянуто два основні недоліки класичного підходу методики FMEA та для їх усунення використано модифікацію, запропоновану Rapinder Sawhney та ін., яка полягає у використанні інтегрального показника «значення оцінки ризиків». Для аналізу ризиків виробничої лабораторії згідно з модифікованою методикою FMEA вибрано окремий шаблон таблиці, представлений у тексті статті. Він містить як елементи FMEA, так і спосіб вирішення критичних показників згідно з принципами LEAN. Такий підхід до роботи лабораторії є вкрай важливим, адже саме від оперативності та точності проведених досліджень залежатиме можливість уникнення прямих утрат для підприємства та випуску безпечної та якісної продукції.


2020 ◽  
Vol 319 ◽  
pp. 01004
Author(s):  
Voraya Wattanajitsiri ◽  
Rapee Kanchana ◽  
Surat Triwanapong ◽  
Kittipong Kimapong

The objective of this research was to study a risk assessment of the rice combine harvester using FMEA technique implementation and suggested the procedures to maintain the parts of the rice combine harvester by analyzing the causes of risk assessment of FMEA. The FMEA was also applied to specify failure causes and effects that occurred in the rice harvester. The obtained data were calculated for a risk priority number (RPN) and then sorted to be a descending order. The high RPN part was analyzed for the causes and effects and then suggested a preventive maintenance in near future. The results revealed that the highest RPN of 576 was found when a chain surface was considered and also showed the maximum risk among the considered parts in the rice combine harvester. While, the lowest RPN of 144 was found when a rice sieve part was considered but this RPN was still higher than that of 100 RPN which was required to specify the preventive maintenance.


2020 ◽  
Vol 12 ◽  
pp. 184797902094243
Author(s):  
Tauseef Aized ◽  
Muhammad Ahmad ◽  
Muhammad Haris Jamal ◽  
Asif Mahmood ◽  
Syed Ubaid ur Rehman ◽  
...  

Nowadays human safety and comfort are the most considerable parameters in designing and manufacturing of a vehicle, that is why every organization ensures the quality and reliability of components used in the vehicle. Leaf spring is also a component of vehicle which plays an important role in human safety and comfort. It acts as a structural member and an integral part of suspension system. It is important to eliminate the failures in designing and manufacturing process of leaf springs because of its importance in functionality and safety of vehicle. In this research, failure mode and effects analysis has been used to analyze and reduce the risks of 42 possible failures that can occur in automotive leaf spring. It starts from determining, classifying, and analyzing all potential failures and then rating them with the help numeric scores. The four numeric scores namely severity, occurrence, detection, and Risk Priority Number (RPN) are used to find the high potential failures of semi-elliptical leaf springs. In the end, actions are recommended for RPN greater than 250, to increase quality and reliably of product.


Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 280 ◽  
Author(s):  
Haixia Zheng ◽  
Yongchuan Tang

Failure mode and effects analysis (FMEA), as a commonly used risk management method, has been extensively applied to the engineering domain. A vital parameter in FMEA is the risk priority number (RPN), which is the product of occurrence (O), severity (S), and detection (D) of a failure mode. To deal with the uncertainty in the assessments given by domain experts, a novel Deng entropy weighted risk priority number (DEWRPN) for FMEA is proposed in the framework of Dempster–Shafer evidence theory (DST). DEWRPN takes into consideration the relative importance in both risk factors and FMEA experts. The uncertain degree of objective assessments coming from experts are measured by the Deng entropy. An expert’s weight is comprised of the three risk factors’ weights obtained independently from expert’s assessments. In DEWRPN, the strategy of assigning weight for each expert is flexible and compatible to the real decision-making situation. The entropy-based relative weight symbolizes the relative importance. In detail, the higher the uncertain degree of a risk factor from an expert is, the lower the weight of the corresponding risk factor will be and vice versa. We utilize Deng entropy to construct the exponential weight of each risk factor as well as an expert’s relative importance on an FMEA item in a state-of-the-art way. A case study is adopted to verify the practicability and effectiveness of the proposed model.


2009 ◽  
Vol 21 (01) ◽  
pp. 61-70 ◽  
Author(s):  
I-Chi Chou ◽  
Hsu-Chin Hsueh ◽  
Ren-Guey Lee

This paper describes an approach for evaluating the risk of components used in the Holter. Holter is a portable device for recording patients' electrocardiogram in medicine. Holter might hurt users as a result of a bad design, and might record incorrectly when malfunction happens. To prevent risk of injury, we analyze the potential failures of the Holter based on the Failure Mode and Effects Analysis, which is a risk assessment technique. Then, we calculate the Risk Priority Number (RPN) of each failure. According to the RPN, we give two strategies for reducing the risk. One is protection, and the other is alarm. The protection system is used to prevent hazards of the Holter from incorrect operations by the user, and the alarm system is used to detect the malfunction of the Holter. The experimental results show that the safety of the Holter is improved with these two circuits.


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