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Failure Mechanisms
Failure causes are defects in design, process, quality, or part application, which are the underlying cause of a failure or which initiate a process which leads to failure. Where failure depends on the user of the product or process, then human error must be considered. Component failure/failure modes A part failure mode is the way in which a component failed "functionally" on the component level. Often a part has only a few failure modes. For example, a relay may fail to open or close contacts on demand. The failure mechanism that caused this can be of many different kinds, and often multiple factors play a role at the same time. They include corrosion, welding of contacts due to an abnormal electric current, return spring fatigue failure, unintended command failure, dust accumulation and blockage of mechanism, etc. Seldom only one cause (hazard) can be identified that creates system failures. The real root causes can in theory in most cases be traced back to some kind of human ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Error
Human error is an action that has been done but that was "not intended by the actor; not desired by a set of rules or an external observer; or that led the task or system outside its acceptable limits".Senders, J.W. and Moray, N.P. (1991) Human Error: Cause, Prediction, and Reduction'. Lawrence Erlbaum Associates, p.25. . Human error has been cited as a primary cause and contributing factor in disasters and accidents in industries as diverse as Nuclear and radiation accidents and incidents, nuclear power (e.g., the Three Mile Island accident), Pilot error, aviation, List of spaceflight-related accidents and incidents, space exploration (e.g., the Space Shuttle Challenger disaster and Space Shuttle Columbia disaster), and Medical error, medicine. Prevention of human error is generally seen as a major contributor to Data integrity, reliability and safety of (complex) systems. Human error is one of the many contributing causes of risk events. Definition Human error refers to somethi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model (abstract)
The term conceptual model refers to any model that is formed after a wikt:concept#Noun, conceptualization or generalization process. Conceptual models are often abstractions of things in the real world, whether physical or social. Semantics, Semantic studies are relevant to various stages of process of concept formation, concept formation. Semantics is fundamentally a study of concepts, the meaning that thinking beings give to various elements of their experience. Overview Concept models and conceptual models The value of a conceptual model is usually directly proportional to how well it corresponds to a past, present, future, actual or potential state of affairs. A concept model (a model of a concept) is quite different because in order to be a good model it need not have this real world correspondence. In artificial intelligence, conceptual models and conceptual graphs are used for building expert systems and knowledge-based systems; here the analysts are concerned to repres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forensic Electrical Engineering
Forensic electrical engineering is a branch of forensic engineering, and is concerned with investigating electrical failures and accidents in a legal context. Many forensic electrical engineering investigations apply to fires suspected to be caused by electrical failures. Forensic electrical engineers are most commonly retained by insurance companies or attorneys representing insurance companies, or by manufacturers or contractors defending themselves against subrogation by insurance companies. Other areas of investigation include accident investigation involving electrocution, and intellectual property disputes such as patent actions. Additionally, since electrical fires are most often cited as the cause for "suspect" fires, an electrical engineer is often employed to evaluate the electrical equipment and systems to determine whether the cause of the fire was electrical in nature. Goals The ultimate goal of these investigations is often to determine the legal liability for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Failure Rate
Failure is the social concept of not meeting a desirable or intended objective, and is usually viewed as the opposite of success. The criteria for failure depends on context, and may be relative to a particular observer or belief system. One person might consider a failure what another person considers a success, particularly in cases of direct competition or a zero-sum game. Similarly, the degree of success or failure in a situation may be differently viewed by distinct observers or participants, such that a situation that one considers to be a failure, another might consider to be a success, a qualified success or a neutral situation. It may also be difficult or impossible to ascertain whether a situation meets criteria for failure or success due to ambiguous or ill-defined definition of those criteria. Finding useful and effective criteria or heuristics to judge the success or failure of a situation may itself be a significant task. Sociology Cultural historian Sco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Failure Modes, Effects, And Diagnostic Analysis
Failure modes, effects, and diagnostic analysis (FMEDA) is a systematic analysis technique to obtain subsystem / device level failure rates, failure modes and diagnostic capability. The FMEDA technique considers: * All components of a design, * The functionality of each component, * The failure modes of each component, * The effect of each component failure mode on the product functionality, * The ability of any automatic diagnostics to detect the failure, * The design strength (de-rating, safety factors), * The impact of any latent fault tests, and * The operational profile (environmental stress factors). Given a component database calibrated with field failure data that is reasonably accurate, the method can predict device level failure rate per failure mode, useful life, automatic diagnostic effectiveness, and latent fault test effectiveness for a given application. The predictions have been shown to be more accurate than field warranty return analysis or even typical field f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
