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Reliability, Availability, Maintainability And Safety
In engineering, reliability, availability, maintainability and safety (RAMS) Norwegian University of Science and Technology is used to characterize a product or system: * Reliability: Ability to perform a specific function and may be given as design reliability or operational reliability * Availability: Ability to keep a functioning state in the given environment * Maintainability: Ability to be timely and easily maintained (including servicing, inspection and check, repair and/ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engineering
Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more specialized List of engineering branches, fields of engineering, each with a more specific emphasis on particular areas of applied mathematics, applied science, and types of application. See glossary of engineering. The term ''engineering'' is derived from the Latin ''ingenium'', meaning "cleverness" and ''ingeniare'', meaning "to contrive, devise". Definition The American Engineers' Council for Professional Development (ECPD, the predecessor of Accreditation Board for Engineering and Technology, ABET) has defined "engineering" as: The creative application of scientific principles to design or develop structures, machines, apparatus, or manufacturing processes, or works utilizing them singly or in combination; or to construct o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability, Availability And Serviceability
Reliability, availability and serviceability (RAS), also known as reliability, availability, and maintainability (RAM), is a computer hardware engineering term involving reliability engineering, high availability, and serviceability design. The phrase was originally used by International Business Machines ( IBM) as a term to describe the robustness of their mainframe computers. Computers designed with higher levels of RAS have many features that protect data integrity and help them stay available for long periods of time without failure This data integrity and uptime is a particular selling point for mainframes and fault-tolerant systems. Definitions While RAS originated as a hardware-oriented term, systems thinking has extended the concept of reliability-availability-serviceability to systems in general, including software. * ''Reliability'' can be defined as the probability that a system will produce correct outputs up to some given time ''t''. Reliability is enhanced by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Integrity Level
Safety integrity level (SIL) is defined as the relative level of risk-reduction provided by a safety function, or to specify a target level of risk reduction. In simple terms, SIL is a measurement of performance required for a safety instrumented function (SIF). The requirements for a given SIL are not consistent among all of the functional safety standards. In the functional safety standards based on the IEC 61508 standard, four SILs are defined, with SIL 4 the most dependable and SIL 1 the least. The applicable SIL is determined based on a number of quantitative factors in combination with qualitative factors such as development process and safety life cycle management. Assignment Assignment of SIL is an exercise in risk analysis where the risk associated with a specific hazard, that is intended to be protected against by a SIF, is calculated without the beneficial risk reduction effect of the SIF. That unmitigated risk is then compared against a tolerable risk target. The di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability-centered Maintenance
Reliability-centered maintenance (RCM) is a concept of maintenance planning to ensure that systems continue to do what their user require in their present operating context. Successful implementation of RCM will lead to increase in cost effectiveness, reliability, machine uptime, and a greater understanding of the level of risk that the organization is managing. Context It is generally used to achieve improvements in fields such as the establishment of safe minimum levels of maintenance, changes to operating procedures and strategies and the establishment of capital maintenance regimes and plans. Successful implementation of RCM will lead to increase in cost effectiveness, machine uptime, and a greater understanding of the level of risk that the organization is managing. John Moubray characterized RCM as a process to establish the safe minimum levels of maintenance. This description echoed statements in the Nowlan and Heap report from United Airlines. It is defined by the tech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Risk Assessment
Broadly speaking, a risk assessment is the combined effort of: # identifying and analyzing potential (future) events that may negatively impact individuals, assets, and/or the environment (i.e. hazard analysis); and # making judgments "on the tolerability of the risk on the basis of a risk analysis" while considering influencing factors (i.e. risk evaluation). Put in simpler terms, a risk assessment determines possible mishaps, their likelihood and consequences, and the tolerances for such events. The results of this process may be expressed in a quantitative or qualitative fashion. Risk assessment is an inherent part of a broader risk management strategy to help reduce any potential risk-related consequences. Need Individual risk assessment Risk assessment are done in individual cases, including patient and physician interactions. Individual judgements or assessments of risk may be affected by psychological, ideological, religious or otherwise subjective factors, which impa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Availability
High availability (HA) is a characteristic of a system which aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period. Modernization has resulted in an increased reliance on these systems. For example, hospitals and data centers require high availability of their systems to perform routine daily activities. Availability refers to the ability of the user community to obtain a service or good, access the system, whether to submit new work, update or alter existing work, or collect the results of previous work. If a user cannot access the system, it is – from the user's point of view – ''unavailable''. Generally, the term ''downtime'' is used to refer to periods when a system is unavailable. Principles There are three principles of systems design in reliability engineering which can help achieve high availability. # Elimination of single points of failure. This means adding or building redundancy into the system so that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hazard Analysis And Critical Control Points
Hazard analysis and critical control points, or HACCP (), is a systematic preventive approach to food safety from biological, chemical, and physical hazards in production processes that can cause the finished product to be unsafe and designs measures to reduce these risks to a safe level. In this manner, HACCP attempts to avoid hazards rather than attempting to inspect finished products for the effects of those hazards. The HACCP system can be used at all stages of a food chain, from food production and preparation processes including packaging, distribution, etc. The Food and Drug Administration (FDA) and the United States Department of Agriculture (USDA) require mandatory HACCP programs for juice and meat as an effective approach to food safety and protecting public health. Meat HACCP systems are regulated by the USDA, while seafood and juice are regulated by the FDA. All other food companies in the United States that are required to register with the FDA under the Public Health ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Failure Rate
Failure rate is the frequency with which an engineered system or component fails, expressed in failures per unit of time. It is usually denoted by the Greek letter λ (lambda) and is often used in reliability engineering. The failure rate of a system usually depends on time, with the rate varying over the life cycle of the system. For example, an automobile's failure rate in its fifth year of service may be many times greater than its failure rate during its first year of service. One does not expect to replace an exhaust pipe, overhaul the brakes, or have major transmission problems in a new vehicle. In practice, the mean time between failures (MTBF, 1/λ) is often reported instead of the failure rate. This is valid and useful if the failure rate may be assumed constant – often used for complex units / systems, electronics – and is a general agreement in some reliability standards (Military and Aerospace). It does in this case ''only'' relate to the flat region of the ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reliability Engineering
Reliability engineering is a sub-discipline of systems engineering that emphasizes the ability of equipment to function without failure. Reliability describes the ability of a system or component to function under stated conditions for a specified period of time. Reliability is closely related to availability, which is typically described as the ability of a component or system to function at a specified moment or interval of time. The reliability function is theoretically defined as the probability of success at time t, which is denoted R(t). This probability is estimated from detailed (physics of failure) analysis, previous data sets or through reliability testing and reliability modelling. Availability, testability, maintainability and maintenance, repair and operations, maintenance are often defined as a part of "reliability engineering" in reliability programs. Reliability often plays the key role in the cost-effectiveness of systems. Reliability engineering deals with the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Failure Mode
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 huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
