Failure Modes Effects Analysis detection identify

A failure mode and effects analysis (also known as failure mode and criticality analysis) examines a high-risk process in advance of an error to detect potential problems. The problems can then be fixed before an error occurs. It is used to discover the potential risk in a product or system. It involves examining a product or system to identify all the ways in which it might fail and allows for a proactive approach to fixing problems before they occur. 

For each step in the process, the team considered what could go tvrong (the failure mode), why the failure might occur (cause) and what could happen if it did occur (effects). An example of the analysis of a failure mode is shown in Box 8.7. A total of 40 failure modes were identified, each of which was then rated on a 10-point scale for Occurrence (how easily it could happen). Severity and Detectability (if it did occur, how likely it is that the failure would go undetected). These three scores are then multiplied together to give a rough... 

The enterprise analyzes and prioritizes potential functional failure modes to define failure effects and identify the need for fault detection and recovery fimctions. Functional reliability models are established to support the analysis of system effectiveness for each operational scenario. Failures, which represent significant safety, performance, or environmental hazards, are modeled to completely understand system impacts. 

The team constructed a map that identified variables at each step of the process. A root cause analysis tool. Failure Mode and Effects Analysis, was used to prioritize the variables that were most frequently associated with errors, that resulted in the most severe errors, and that were the most difficult to detect. 

A very important and powerful reliability analysis tool is the FMECA. FMECA identifies all potential weaknesses of a system by systematically identifying all the potential failure modes, their causes, failure frequencies, effects of the failure modes to the item, system and aircraft, severities of those effects, detection method of the failures and finally possible compensating provisions of the failures. There are several different standards and guidelines available which outlines how a EMECA can be performed and documented. Eor the aircraft programs MIL-STD-1629 A can be used as a reference and can be tailored in accordance with the program needs. (Department of Defense 1998) Steps to be followed while performing a EMECA, is shown in Figure 4. 

The marine industry is recognising the need for powerful techniques that can be used to perform risk analysis of marine systems. One technique that has been applied in both national and international marine regulations and operations is Failure Mode and Effects Analysis (FMEA). This risk analysis tool assumes that a failure mode occurs in a system/component through some failure mechanism. The effect of this failure is then evaluated. A risk ranking is produced in order to prioritise the attention for each of the failure modes identified. The traditional method utilises the Risk Priority Number (RPN) ranking system. This method determines the RPN by finding the multiplication of factor scores. The three factors considered are probability of failure, severity and detectability. Traditional FMEA has been criticised to have several weaknesses. These weaknesses are addressed in this Chapter. A new approach, which utilises the fuzzy rules base and grey relation theory, is presented. 

FMEA is used to assist analysts to perform hazard analyses and it is regarded as a supplement rather than a replacement for hazard analyses. Safety analysts can use FMEA to verify that all safety critical hardware has been addressed in the hazard analyses. The FMEA for hardware systems is an important technique for evaluating the design and documenting the review process. All credible failure modes and their resultant effects at the component and system levels are identified and documented. Items that meet defined criteria are identified as critical items and are placed on the Critical Item List (CEL). Each entry of the CIL is then evaluated to see if design changes can be implemented so that the item can be deleted from the CIL. Items that cannot be deleted from the CIL must be accepted by the programme/project, based on the rationale for acceptance of the risk. The analysis follows a well-deflned sequence of steps that encompass (1) failure mode, (2) failure effects, (3) causes, (4) detectability, (S) corrective or preventive actions, and (6) rationale for acceptance. 

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