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Mean Time To Recovery
Mean time to recovery (MTTR) tp://download.intel.com/design/servers/ISM/docs/317987.pdf INTEL call for Mean-Time-to-''Repair'' on page 4 left. is the average time that a device will take to recover from any failure. Examples of such devices range from self-resetting fuses (where the MTTR would be very short, probably seconds), to whole systems which have to be repaired or replaced. The MTTR would usually be part of a maintenance contract, where the user would pay more for a system MTTR of which was 24 hours, than for one of, say, 7 days. This does not mean the supplier is guaranteeing to have the system up and running again within 24 hours (or 7 days) of being notified of the failure. It does mean the average repair time will tend towards 24 hours (or 7 days). A more useful maintenance contract measure is the maximum time to recovery which can be easily measured and the supplier held accountably. Note that some suppliers will interpret MTTR to mean 'mean time to respond' and ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arithmetic Mean
In mathematics and statistics, the arithmetic mean ( ) or arithmetic average, or just the ''mean'' or the ''average'' (when the context is clear), is the sum of a collection of numbers divided by the count of numbers in the collection. The collection is often a set of results of an experiment or an observational study, or frequently a set of results from a survey. The term "arithmetic mean" is preferred in some contexts in mathematics and statistics, because it helps distinguish it from other means, such as the geometric mean and the harmonic mean. In addition to mathematics and statistics, the arithmetic mean is used frequently in many diverse fields such as economics, anthropology and history, and it is used in almost every academic field to some extent. For example, per capita income is the arithmetic average income of a nation's population. While the arithmetic mean is often used to report central tendencies, it is not a robust statistic, meaning that it is greatly influe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redundant Array Of Independent Disks
Raid, RAID or Raids may refer to: Attack * Raid (military), a sudden attack behind the enemy's lines without the intention of holding ground * Corporate raid, a type of hostile takeover in business * Panty raid, a prankish raid by male college students on the living quarters of female students to steal panties as trophies * Police raid, a police action involving the entering of a house with the intent to capture personnel or evidence, often taking place early in the morning *Union raid, when an outsider trade union takes over the membership of an existing union Arts, entertainment, and media Films * ''Raid'' (1947 film), an East German film * ''Raid'' (2003 film), a 2003 Finnish film * ''Raid'' (2018 film), an Indian period crime thriller Gaming * Raid (gaming), a type of mission in a video game where a large number of people combine forces to defeat a powerful enemy * ''Raid'' (video game), a Nintendo Entertainment System title released by Sachen in 1989 * '' Raid over Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Time To Repair
Mean time to repair (MTTR) is a basic measure of the maintainability of repairable items. It represents the average time required to repair a failed component or device. Expressed mathematically, it is the total corrective maintenance time for failures divided by the total number of corrective maintenance actions for failures during a given period of time. It generally does not include lead time for parts not readily available or other Administrative or Logistic Downtime (ALDT). In fault-tolerant design, MTTR is usually considered to also include the time the fault is latent (the time from when the failure occurs until it is detected). If a latent fault goes undetected until an independent failure occurs, the system may not be able to recover. MTTR is often part of a maintenance contract, where a system whose MTTR is 24 hours is generally more valuable than for one of 7 days if mean time between failures is equal, because its Operational Availability is higher. However, in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Time Between Failures
Mean time between failures (MTBF) is the predicted elapsed time between inherent failures of a mechanical or electronic system during normal system operation. MTBF can be calculated as the arithmetic mean (average) time between failures of a system. The term is used for repairable systems while mean time to failure (MTTF) denotes the expected time to failure for a non-repairable system. The definition of MTBF depends on the definition of what is considered a failure. For complex, repairable systems, failures are considered to be those out of design conditions which place the system out of service and into a state for repair. Failures which occur that can be left or maintained in an unrepaired condition, and do not place the system out of service, are not considered failures under this definition. In addition, units that are taken down for routine scheduled maintenance or inventory control are not considered within the definition of failure. The higher the MTBF, the longer a system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Down Time
In organizational management, mean down time (MDT) is the average time that a system is non-operational. This includes all downtime associated with repair, corrective and preventive maintenance, self-imposed downtime, and any logistics or administrative delays. Description The inclusion of delay times distinguishes mean down time from mean time to repair (MTTR), which includes only downtime specifically attributable to repairs. Mean Down Time key factors: # SYSTEM FAILURE ## ''Identification & Recovery Time.'' First, the fact that the system is down must be identified, and maintainers notified & brought to action ## ''Fault detection and isolation.'' The problem must be identified and the faulty part identified. ## ''Parts Procurement.'' Replacement parts needed (if any) must be obtained ## ''System Repair.'' Faulty parts must be replaced or repaired. # SCHEDULED DOWNTIME ## ''Preventive Maintenance.'' Preventive maintenance checks are often intrusive and require the system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Service-level Agreement
A service-level agreement (SLA) is a commitment between a service provider and a customer. Particular aspects of the service – quality, availability, responsibilities – are agreed between the service provider and the service user. The most common component of an SLA is that the services should be provided to the customer as agreed upon in the contract. As an example, Internet service providers and telcos will commonly include service level agreements within the terms of their contracts with customers to define the level(s) of service being sold in plain language terms. In this case, the SLA will typically have a technical definition of ''mean time between failures'' (MTBF), ''mean time to repair'' or ''mean time to recovery'' (MTTR); identifying which party is responsible for reporting faults or paying fees; responsibility for various data rates; throughput; jitter; or similar measurable details. Overview A service-level agreement is an agreement between two or more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Failure
Failure is the state or condition of not meeting a desirable or intended objective (goal), objective, and may be viewed as the opposite of Success (concept), 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, 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 significan ... [...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] |
Free On-line Dictionary Of Computing
The Free On-line Dictionary of Computing (FOLDOC) is an online, searchable, encyclopedic dictionary of computing subjects. History FOLDOC was founded in 1985 by Denis Howe and was hosted by Imperial College London. In May 2015, the site was updated to state that it was "no longer supported by Imperial College Department of Computing". Howe has served as the editor-in-chief since the dictionary's inception, with visitors to the website able to make suggestions for additions or corrections to articles. Open sourcing The dictionary incorporates the text of other free resources, such as the Jargon File, as well as covering many other computing-related topics. Due to its availability under the GNU Free Documentation License, a copyleft license, it has in turn been incorporated in whole or part into other free content projects, such as Wikipedia. Recognition * This site's brief 2001 review by a Ziff Davis Ziff Davis, Inc. is an American digital media and internet company. F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
