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A systematic failure mode effects and criticality analysis for offshore wind turbine systems towards integrated condition based maintenance strategies

A systematic failure mode effects and criticality analysis for offshore wind turbine systems towards integrated condition based maintenance strategies

In the next question, answered in step 5, the information about the likelihood of a failure scenario to occur is documented. The likelihood of occurrence assessment is a vital part of any risk assessment. Generally, the likelihood of occurrence (or probability of occurrence) can be assessed quantitatively, semi-quantitatively or qualitatively. Quantitative and semi-quantitative approaches are applicable if there is an operating track record available of the item under consideration providing statistically viable information; i.e. the information about an items ’ reliability can be obtained from actual data records. This ap- proach is not applicable for items which have been in operation for a short period of time. Therefore, qualitative engineering judgment was used for the assessment of the likelihood of occurrence of the given scenarios. The mentioned judgments were supported by numerical calculations, other modelling techniques, or experience from other fi elds of application of a similar technology where possible. Within this research project, the assets under consideration are of differing ages; i.e. for some assets, an operating track record of several years is available, whereas others have been in operation only for a relatively short period of time or not even built. Due to this di ff ering character- istic, a qualitative assessment approach has been chosen for the like- lihood of occurrence evaluation. Table 1 summarizes the three levels that have been used:

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Problem Solving Of Foot Switches Processes Using Failure Mode And Effects Analysis

Problem Solving Of Foot Switches Processes Using Failure Mode And Effects Analysis

An FMEA becomes a Failure Modes, Effects and Criticality Analysis (FMECA) if criticalities or priorities are assigned to the failure mode effects. The FMEA technique is used as an integral part of an RCM (Reliability Centered Maintenance) analysis. One main idea of RCM is to prevent failures by eliminate or reduce the failure causes. The FMEA analysis should therefore focus on the failures causes and failure mechanisms. When the failure causes and failure mechanisms are identified for each failure mode, it will be possible to suggest time based preventive maintenance actions, or condition monitoring techniques to reduce the resulting failure mode. Engineer and managers use this tool during the design phase of a product or process to help them establish priorities and resource allocation to be applied to the most critical aspects of a product’s design. During the design process, a development team identifies possible product failures that might generate a negative result such as an inconvenience to a customer, loss of money for a company, or even injury to a user. Once these potential failures are identified, they are assigned a priority based on their likelihood and severity. This allows the development team to focus on improving aspects of the design that will provide the most benefit to the company. A company may use this tool for processes, products or any other complex system that may have multiple points of failure.

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RELIABILITY ANALYSIS OF REACTOR-REGENERATOR UNIT OF THE KADUNA REFINERY USING FAILURE MODES EFFECTS AND CRITICALITY ANALYSIS (FMECA)

RELIABILITY ANALYSIS OF REACTOR-REGENERATOR UNIT OF THE KADUNA REFINERY USING FAILURE MODES EFFECTS AND CRITICALITY ANALYSIS (FMECA)

The neglect of most process industries to assess the reliability of their process equipment had led to high financial losses.As a result, this study aims at systematically analyzing the effectiveness and reliability of the Reactor-regenerator unit of the Kaduna Refining and Petrochemicals (KRPC), Fluid Catalytic Cracking Unit (FCCU), using the Failure mode, effects and criticality analysis (FMECA). The unit failure and its effect were identified through twelve (12) sub-units (air heater, riser, disengager, regenerator, stripper, spent catalyst plug valve, regenerator catalyst plug valve, flur gas slide valve, fresh catalyst drum, wash water pump, used catalyst drum, and fractionator primary condenser), using the failure mode effects analysis (FMEA). Both quantitative and qualitative criticality analysis (CA) were used to determine the effectiveness and reliability of the unit (reactor-regenerator). For the qualitative analysis, items risk priority number (RPN) were computed and it was found that, five (5) of the sub-units (air heater, riser, spent catalyst plug valve, regeneration catalyst plug valve, and flue gas slide valve) had their RPN>300, with air heater having the highest RPN of 724. For the quantitative analysis, items criticality number (Cr) were computed and it was found that most of the sub-units had their Cr>0.002. In addition, the results of the criticality matrix showed that, sixteen (16) out of the twenty four (24) failure modes identifiedwere above or closely below the criticality line. Therefore, the effectiveness and reliability of the unit is low. As such, sub-units with RPN>300 and failure modes above or closely below the criticality line were recommended for replacement or predictive maintenance.

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Reliability Analysis Techniques Based on the FTA for Reactor-Regenerator System

Reliability Analysis Techniques Based on the FTA for Reactor-Regenerator System

In reliability assessment of the reactor systems, most studies related to how to construct fault trees and how to calculate the probability of equipment failure were carried out (Dai,1995 and 1998 ). However, the disadvantages of reliability assessment by FTA aims to identify the most significant groups of basic events rather than to provide exact risk ranking to all the basic events. There is no precise failure mode of the individual basic event in the different equipment item. FTA is unable to be used to evaluate both the likelihood and the consequence of the set of events in each scenario as well. An approach was developed in which the significance of the basic events were established by counting the number of AND gates (Xie,2000), but in practice, most fault trees consist of a majority of OR gates and maybe a few AND gates. The limitation of the approach is that it is more qualitative and does not provide an actual value compared with the importance measures. On the assessment of availability of a FCCU through simulation, Thangamani and Narendran (1994) studied fault tree by identifying the subsystems and components which are critical to the availability of a plant. Failure Modes, Effects and Criticality Analysis (FMECA) is another technique of reliability analysis and is usually performed to provide a better understanding of the risk assessment for engineering system. The main limitation of the FMECA is that it does not provide quantitative information or how much more significant one basic event is compared to the rest of the basic events in the system. The purpose of this paper is to propose a new approach by combining FTA and FMECA, and making use of the technique for improving the reliability of reactor-regenerator system, ranking outcome of relative probability of every basic event, finding out the most important basic element of influence system reliability seriously and using reliability as a basis for prioritizing and managing an inspection program, where equipment items to be inspected are ranked according to their risk.

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Risk Analysis Method: FMEA/FMECA in the Organizations

Risk Analysis Method: FMEA/FMECA in the Organizations

2.1. Definitions of FMEA/FMECA: Failure Modes and Effects Analysis (FMEA) and Failure Modes, Effects and Criticality Analysis (FMECA) are methodologies designed to identify potential failure modes for a product or process before the problems occur, to assess the risk. Ideally, FMEA’s are conducted in the product design or process development stages, although conducting an FMEA on existing products or processes may also yield benefits. The FMEA team determines, by failure mode analysis, the effect of each failure and identifies single failure points that are crucial. It may also rank each failure according to the criticality of a failure effect and its probability of occurring. The FMECA is the result of two steps:

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Proposing a method to reduce technical downtime at Quaker Oats

Proposing a method to reduce technical downtime at Quaker Oats

In the second module (Section 4.2) the systems and the components will be identified. Here the systems will be determined in which the two packing machines can be classified. This is done by a questionnaire filled in by twelve people, nine from Maintenance and three from Production. The division is chosen because people from Maintenance use the classification the most and should therefore have the most impact. The critical components will also be determined in the second module to determine where the focus should be on. This is done with the help of a qualitative failure mode effect and criticality analysis (FMECA) based on expert knowledge and complemented with quantitative data. Quaker Oats its data alone wouldn’t be enough for the FMECA due to reasons mentioned before. We therefore use qualitative data and complement it with quantitative data. We use the maintenance specialist, the work planner and incidentally, due to their time, engineers. The FMECA uses a risk priority number (RPN) to indicate what failure mode gets priority in terms of analysing, the higher the RPN, the higher the priority. The short-term uses of the FMECA are to identify the critical or hazardous conditions, potential failure modes, need for failure detection and identifying the effects of the failures. The long-term uses are to help create a maintenance concept and for reliability analysis as well as records of this analysis. In the rest of the criticality analysis of CIBOCOF, multiple factors are used to indicate if the part is critical or not. We do not have enough information to perform such a criticality analysis, so we will only calculate the RPN and based on the RPN determine what actions to take. The RPN can be determined by multiple ways and we will create our own way, see Section 4.2.2. In general, the RPN is a component of scores from severity (S), occurrence (O) and detection (D). The scores per component usually range between 1-10 or anything in between. In the third module (Section 4.3) the maintenance policy will be chosen, as described in Section 3.3, and parameters for the maintenance tasks are determined, like maintenance intervals. Expert opinion will be used to determine maintenance intervals based on the average failure interval. The framework of Gits (1992) goes further and uses a technique to limit the number of maintenance intervals and cluster maintenance tasks to reduce set-up cost, but as said in 3.5.1, this is not yet possible for Quaker Oats.

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FMEA ( Failure Mode and Effects Analysis ) and FMECA

FMEA ( Failure Mode and Effects Analysis ) and FMECA

Abstract— IT risk management currently plays more and more important role in almost all aspects of contemporary organizations’ functionality. It requires reliable and cyclical realization of its key task which is risk analysis. Literature of subject presents problems of risk analysis in different way, the most often skipped or selectively treated the problem of quantitative methods application for the purpose of risk analysis. The article presents the issue of one of the most significant stages of risk analysis which is IT risk assessment, especially focusing on chosen quantitative methods such as ALE (Annual Loss Expected) method, Courtney method, Fisher’s method, using survey research ISRAM model (Information Security Risk Analysis Method) and other derived ratios. There were also shortly presented chosen qualitative methods – FMEA (Failure Mode and Effects Analysis) and FMECA (Failure Mode and Effects Criticality Analysis), NIST SP 800-30 method and CRAMM methodology.

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Risks Prioritization using FMEA Method  A Case Study

Risks Prioritization using FMEA Method A Case Study

important role of every business or industrial, since it must be supplied to cove with the full consumption on demand sites. A survey has been conducted to identify the chances of failures of various machinery/ equipment which may occur in thermal Power Plant at Jaiswal Neco Industries Limited, Raipur. Many factors for failure are come to be known, out of which some major critical factors are identified for which FMEA is conducted. Failure Modes and Effects Analysis (FMEA) is methodology for analyzing potential reliability problems early in the development cycle where it is easier to take actions to overcome these issues, thereby enhancing reliability through design. Failure mode, effects and criticality analysis (FMECA) is the also most popular systematic assessment of a process (product) that enables us to determine the location and the mechanism of potential failures, with the aim of preventing process (product) failures. FMEA is precisely an analytical methodology used to ensure that potential problems have been considered and addressed throughout the product and process development cycle. A process or a design should be analyzed first before it is implemented and also before operating a machine the failure modes and effect must be analyzed critically. A comparative analysis of various risks factors reduces the chance of its occurrence. The main motive of this paper is risk Prioritization using FMEA method, which are more severe for the Company. Finally the most risky failure according to the RPN numbers is found and the cause and effects along with the preventive measures are tabulated.

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Reliability Investigation of Steam Turbine Used In Thermal Power Plant

Reliability Investigation of Steam Turbine Used In Thermal Power Plant

The identification of the most critical components of steam turbine during operation is taking into consideration in the second step. The failure mode and effect analysis (FMEA) is always based on a table which contains mainly four columns. In the first column the component under study is listed and in second column the physical modes of failure are given. The potential causes of failure modes of each components of the functional tree are describe in third column. Finally, the last column lists the effects of each failure mode are categorized according to the criticality scale, which states the degradation degree in the turbine operation. Lewis (1987) has proposed FMECA (Failure Mode and Effective criticality Analysis) approach to evaluate the component failure effect on the turbine operation The FMECA analysis was performed for each component listed in the end of a given branch of the functional tree. For present analysis criticality index is classified into three main severity levels: marginal, critical and catastrophic For the definition of the system degradation, the FMECA analysis uses a numerical code, usually ranking from 1 to 10. Higher the number, criticality of the component is higher

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Analysis of Computer Network Reliability and Criticality: Technique and Features

Analysis of Computer Network Reliability and Criticality: Technique and Features

The classification of failure modes, causes, effects and means of safety and fault-tolerance ensuring for the network functional elements is obtained by using the FME(C)A-format. The various means of safety and fault- tolerance ensuring of the network hardware and software are indicated in the last table column. The probability and the severity for each failure mode of specified com- puter network are determined on the basis of statistical information or expert estimations. It allows to construct a criticality grid, and with its help to execute a qualitative analysis of CCN reliability, to determine a set of the most critical failures and means for their recovery.

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Risks Prioritization using FMEA Method  A Case Study

Risks Prioritization using FMEA Method A Case Study

important role of every business or industrial, since it must be supplied to cove with the full consumption on demand sites. A survey has been conducted to identify the chances of failures of various machinery/ equipment which may occur in thermal Power Plant at Jaiswal Neco Industries Limited, Raipur. Many factors for failure are come to be known, out of which some major critical factors are identified for which FMEA is conducted. Failure Modes and Effects Analysis (FMEA) is methodology for analyzing potential reliability problems early in the development cycle where it is easier to take actions to overcome these issues, thereby enhancing reliability through design. Failure mode, effects and criticality analysis (FMECA) is the also most popular systematic assessment of a process (product) that enables us to determine the location and the mechanism of potential failures, with the aim of preventing process (product) failures. FMEA is precisely an analytical methodology used to ensure that potential problems have been considered and addressed throughout the product and process development cycle. A process or a design should be analyzed first before it is implemented and also before operating a machine the failure modes and effect must be analyzed critically. A comparative analysis of various risks factors reduces the chance of its occurrence. The main motive of this paper is risk Prioritization using FMEA method, which are more severe for the Company. Finally the most risky failure according to the RPN numbers is found and the cause and effects along with the preventive measures are tabulated.

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BUSINESS PROCESS REENGINEERING TO IMPROVE PROCESS ALIGNMENT & INFORMATION SYSTEM 
PLATFORM AT STAINLESS EQUIPMENT COMPANY

BUSINESS PROCESS REENGINEERING TO IMPROVE PROCESS ALIGNMENT & INFORMATION SYSTEM PLATFORM AT STAINLESS EQUIPMENT COMPANY

In this paper proposed FMECA models in determining the critical components of Navigation Radar. Failure Mode Effect and Criticality Analysis (FMECA) is used as a methodology to identify and analyze all potential failure modes of various parts of the system, the effects of the failure of the system, how to avoid failure and to reduce the impact of failure on the system. Based on the model is obtained Risk Priority Number (RPN) that is used as a reference value in determining the critical components. RPN value of each component is analyzed by Risk Matrix, from 27 (twenty-seven) components that have been identified, There are obtained seven (7) components that are considered critical: Modulator, Power Supply Scanner, Diodes Limiter, Magnetron, Receiver, Motor, and Circulator. The modulator has the highest RPN value, 24180 and Plotter Control Circuit has the lowest RPN value, 3289.

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The improvement of Failure Mode, Effects and Criticality Analysis at Grolsch

The improvement of Failure Mode, Effects and Criticality Analysis at Grolsch

bad quality from going to the market. Blockades destroyed and blockades reworked do have a target and blockades released do not have a target. Every 30 minutes a batch of test bottles are put in every line. Every bottle has a certain defect and the machines should eject those bottles. If not, the machine apparently does not work properly and then the batch of the previous 30 minutes will be blocked. Knowing the speed of the line, which is usually expressed as bottles/cans/kegs per hour, you could theoretically calculate the amount of blocked products if you could estimate the amount of blockades due to the test bottles. But what you do not know, is the ratio between released products (released after being blocked), reworked products (reworked after being blocked) and destroyed products (destroyed after being blocked). When determining which products will be released, which products will be reworked and which products will be destroyed, there is a lot of subjectivity. Someone needs to check all the bottles/cans/kegs manually and he or she determines which of these three categories the beer falls in. Because we do not know that ratio, we cannot put a target on the different categories looking at blocked products. On top of this problem, the blockades are measured in colli, which is the customer’s buying unit: this can be a 4 pack, a sixpack, a 12-pack, a crate, a keg (19,5L, 30L and 50L) etc. If just one unit would be made on every line, we could make a line division in the FMECA. But unfortunately that is not the case. Then we have to work with averages of colli and this will yield a result which is too inaccurate. I also looked at Beer loss (see Table 4) which is a target on Packaging as well as on Brewing. This KPI again has the same problem as the KPI Blocked products; it is impossible to estimate the amount of beer loss because of a mechanical failure. Another problem with beer loss, is that it only represents category 2 (Table 18

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Failure Mode Effect Analysis and Parameter Op...

Failure Mode Effect Analysis and Parameter Op...

Projection welding using capacitor discharge projection welding machine is gaining popularity in production of sheet metal works in industry. It is one of the most economical methods of projection welding ever known. Projection welding is widely used in fabrication of pump impellers for bottling plants, milk plants and fabrication of automobiles bodies in auto industry. The quality of projection welded joint plays a vital role in the durability and performance of pump impeller. Therefore, it becomes important to study the process parameters involved in the production of projection welded pump impellers, so that the quality of impellers improved and rejection rate due various reasons may reduced. M/s Flowguard, Gurgaon is engaged in production of multistage mineral water pumps with an increasing turnover, 8.7 crores last year. Main factors causing rejection of impeller were power, wear & tear welding electrode, improper cleaning of impeller plates and weak strength of the welded joint. Failure mode effect analysis (FMEA) was done to determine the risk priority number (RPN) against each cause and factor with higher RPN was selected for improvement.

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Correlation Between DFMEA And Process Capability At Automotive Part Supplier

Correlation Between DFMEA And Process Capability At Automotive Part Supplier

Tay and Lim (2006) explained that according to Chrysler Corporation et al. (1995), FMEA can be described as a systemized group of activities intended to recognize and to evaluate the potential failures of a product/process and its effects. Besides, FMEA identifies actions which can eliminate or reduce the chances of potential failures from recurring. It also helps users to identify the key design or process characteristics that require special controls for manufacturing, and to highlight areas for improvement in characteristic control or performance (Ireson et al., 1995).

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Remanufacturing Analysis By Using Failure Mode And Effects Analysis (FMEA) For Engine Block

Remanufacturing Analysis By Using Failure Mode And Effects Analysis (FMEA) For Engine Block

Over this recent year, a growing population that increase the economic development, capacity of landfills and critical environmental impact are gaining the importance role of remanufacturing activities. Moreover, many durable products are disposed in landfills at the end of their useful lives without undergoing by any recovery process that affect the landfill space has been decreasing in all over the world including by our country. Remanufacturing is the process by which used products are returned to their new state with minimum waste and expenditure on materials and energy. This study is to learn and analyze the concept of remanufacturing practice in automotive sector. Malaysians have been generated wastes at a manufacturing sector especially in the automotive sector. On top of that, the conventional remanufacturing systems that have been constructed in Malaysia are not widely marketed and lack of practical applications. This study provides a remanufacturing analysis for improvement to the automotive sectors on engine block. Furthermore, this study presents the information based on the discussion of Failure Mode and Effects Analysis (FMEA) to encourage the implementation of remanufacturing activities. By making the remanufacturing activities possible to implement efficiently, manufacturer may decrease their production costs, decrease refuse and landfill materials, and increase their quality management.

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Perspectives on Safety Critical Computing Systems

Perspectives on Safety Critical Computing Systems

We take as example the CEI/IEC 61508 which recommends the usage of test case design techniques depending on the SIL of a system. This standard defines four integrity levels: SIL4, SIL3, SIL2 and SIL1, where SIL4 is the most critical. For a SIL4 classified system, the standard says that the use of equivalence partitioning is highly recommended as part of the functional testing [Fig 1]. Furthermore the use of boundary value analysis is highly recommended, while the use of cause-effect graph and error guessing are only recommended. For white-box testing the level of coverage is highly recommended, though the standard does not say which level of which coverage. The recommendations are less and less strict as we come down the SILs in the standard. For highly safety- critical system the testers may be required to deliver a compliance statement or matrix, explaining how the pertaining regulations have to be follow and fulfilled.

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Implimentation Of Poka Yoke Through DFMEA Stage For Sme Industry In Malaysia

Implimentation Of Poka Yoke Through DFMEA Stage For Sme Industry In Malaysia

Poka Yoke is useful during the DFMEA which will function as the detection approaches of the failure during mass production. It is not possible to eliminate all the mistakes that people make. People are not mistake proof but the organization can avoid this human error from reaching to the customer by using this method. Mistakes can be stopped as soon as they happen at least. Poka Yoke is a very simple method in the nature. For those company strive for Zero Defect, this study will be useful for them. In this case, a SME industry had been chosen in order to apply and analyze the Poka Yoke effectiveness.

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Effect analysis of reliability, availability, maintainability and safety (rams) of train operation

Effect analysis of reliability, availability, maintainability and safety (rams) of train operation

In this project, we consider the problem arises in the train operation system that will disturb the train operation. For KTMB that runs multiple train units in rail network, predicting and keeping a required level of train operation availability is a challenging task. The stochastic nature of train breakdowns and the corrective maintenance to fix them are problems to keep track of availability of the train operation. If more trains are withdrawn from an operation due to failure, the train operator cannot provide the required transportation capacity to cover the scheduled services. To enhance the availability of the operation, the management needs to keep reliability of trains.

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Failure Mode and Criticality Analysis of Transmission System

Failure Mode and Criticality Analysis of Transmission System

Engine failure is loss or non-conformance of an expected functional performance due to malfunctioning of a subsystem or component.Every product or process has modes of failure.Several systematic methodologies have been developing to quantify the effect and impact of failures.Failure analysis performs dew to product and process development.

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