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...e often expressed in a linguistic way (such as ‘likely’ , ‘important’, ‘very high’ and etc); (iii) In the traditional FMEA methodology, the three risk factors are assumed to have the same importance (=-=Braglia, 2000-=-). However, it is observed that many O&M experts give more preference to the ‘fault detection’ factor. So, the results of the traditional FMEA methodology may not necessarily represent the true risk p...

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...ained by simply multiplying these quantified parameters. This method is mostly preferred bysthe manufacturing industries such as automotivescompanies, domestic appliance firms, and tire companies etc =-=[7]-=-.sEven though RPN evaluation with FMECA issprobably the most popular technique for reliabilitysand failure mode analysis, several problems are associated with its practical implementation. Besides the...

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...vability. A more appealing approach would be to choose a model based on the physics of failures and the characteristics of the operating environment. Ref. [9] gives a few reasons on why Taguchi methods have not been employed commonly while repairing the failures. The reasons are the performance of a service process is very difficult to measure accurately where the outcome of a service process is inherently much more inconsistent in quality than its manufacturing counterparts. Furthermore, the service process has more ‘noise factors’ that are difficult, expensive or impossible to control. Then [10] modified the model of operation in the service or technical center, where they discussed Six-sigma methodology to measure machine downtime to produce products with zero defects. Usage of the 80-20 rule which states 20% of the defects account for 80% of the quality loss applied to minimize the number of experiments necessary to study the effects of various factors on the performance of a process. Ref. [11] develops a robust regression metamodel for a maintenance float policy which was originally referred to “repairman’s problem”. All the factors affecting the system were identified and classif...

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...litative and quantitative data [12, 13] for determining the hierarchy, structure, and quantification of problem. AHP Hindawi Publishing Corporation Mathematical Problems in Engineering Volume 2015, Article ID 956757, 14 pages http://dx.doi.org/10.1155/2015/956757 2 Mathematical Problems in Engineering deconstructs a problem from higher to low layer with hierarchy relationships within complicated problems, by a series of simple comparisons to address complex decisionrelated problems, andmany studies have demonstrated that it is a powerful multicriteria decision-making tool for complex problems [14]. Based on these characteristics, AHP has been applied to obtain solutions for complicated problems in simulator research, for which many studies have been published. For example, Bosch-Mauchand et al. [15] used the AHP value chain simulator to help experts make decisions with regard to industrial product design and industrial process design. Ding et al. [16] applied AHP and load-shedding scheme methods to determine the critical factors of power loading using simulator experiments with a destroyer power system. Lu et al. [17] developed a collision avoidance decision model with the AHP method t...

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...e quality of the function, rather than total elimination of the auto positioning ability. Loss of the DP computer, however, will cause loss of function. Based on this, “DP sensors” will be assigned screening grade 0.5, while “DP computer” will be assigned screening grade 0. In the next stage, for a subfunction with grade 0, a criticality analysis of components should be carried out. As mentioned in respect of criticality at the component level, appropriate importance measurements need to be selected. While recognizing all the limitations of using risk priority numbers (RPN), we found that RPN [22,38] could provide an acceptable level of analysis in this step. RPN is a numeric assessment of risk assigned to a process, or steps in a process, whereby a team assigns a numeric value to each failure mode (for example from 1 to 10) to quantify the likelihood of occurrence, likelihood of detection, and severity of impact [11,12,39]. These rankings are then multiplied to give the RPN. Failure modes having a high RPN are assumed to be more important and are given a higher priority than those having a lower RPN. Calculation of RPN is described in MIL-STD-1629A [10]. Past experience and engineering j...

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...dology moresunderstandable, realistic and practical for wind farm managers;siv. The relative importance weights of the risk factors need to be taken into account in thestraditional methodologies (see =-=[36]-=-), but in the CPN method, there is no need to include anysweighting factors for O, C and D;sv. The use of CPN analysis enables the wind farm managers to compare different wind turbinessystems with dif...