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Western Electric Rules
The Western Electric rules are decision rules in statistical process control for detecting out-of-control or non- random conditions on control charts. Locations of the observations relative to the control chart control limits (typically at ±3 standard deviations) and centerline indicate whether the process in question should be investigated for assignable causes. The Western Electric rules were codified by a specially-appointed committee of the manufacturing division of the Western Electric Company and appeared in the first edition of a 1956 handbook, that became a standard text of the field. Their purpose was to ensure that line workers and engineers interpret control charts in a uniform way. Motivation The rules attempt to distinguish unnatural patterns from natural patterns based on several criteria: The absence of points near the centerline is identified as a mixture pattern. The absence of points near the control limits is identified as a stratification pattern. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decision Rules
A decision tree is a decision support tool that uses a tree-like model of decisions and their possible consequences, including chance event outcomes, resource costs, and utility. It is one way to display an algorithm that only contains conditional control statements. Decision trees are commonly used in operations research, specifically in decision analysis, to help identify a strategy most likely to reach a goal, but are also a popular tool in machine learning. Overview A decision tree is a flowchart-like structure in which each internal node represents a "test" on an attribute (e.g. whether a coin flip comes up heads or tails), each branch represents the outcome of the test, and each leaf node represents a class label (decision taken after computing all attributes). The paths from root to leaf represent classification rules. In decision analysis, a decision tree and the closely related influence diagram are used as a visual and analytical decision support tool, where the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rule 2 - Western Electric Control Chart
Rule or ruling may refer to: Education * Royal University of Law and Economics (RULE), a university in Cambodia Human activity * The exercise of political or personal control by someone with authority or power * Business rule, a rule pertaining to the structure or behavior internal to a business * School rule, a rule that is part of school discipline * Sport rule, a rule that defines how a sport is played * Game rule, a rule that defines how a game is played * Moral, a rule or element of a moral code for guiding choices in human behavior * Norm (philosophy), a kind of sentence or a reason to act, feel or believe * Rule of thumb, a principle with broad application that is not intended to be strictly accurate or reliable for every situation * Unspoken rule, an assumed rule of human behavior that is not voiced or written down * Slide rule, a mechanical analog computer Science * Rule of inference or transformation rule, a term in logic for a function which takes premis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quality Control Tools
Quality may refer to: Concepts *Quality (business), the ''non-inferiority'' or ''superiority'' of something *Quality (philosophy), an attribute or a property *Quality (physics), in response theory *Energy quality, used in various science disciplines *Logical quality, philosophical categorization of statements *Service quality, comparison of expectations with performance in a service *Vapor quality, in thermodynamics, the ratio of mass of vapor to that of vapor and liquid *Data quality, refers to the condition of a set of values of qualitative or quantitative variables Practices *Quality assurance (QA) *Quality control (QC) Places *Quality, Kentucky, an unincorporated community Brands and enterprises *Quality Comics, an American comic book publisher between 1939 and 1956 *Quality Communications, a comic book publisher started in 1982 *Quality Records, a Canadian entertainment company Music * ''Quality'' (CDQ album), 2016 * ''Quality'' (Talib Kweli album), 2002 *"Quality", a song ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Westgard Rules
The Westgard rules are a set of statistical patterns, each being unlikely to occur by random variability, thereby raising a suspicion of faulty accuracy or precision of the measurement system. They are used for laboratory quality control, in "runs" consisting of measurements of multiple samples. They are a set of modified Western Electric rules, developed by James Westgard and provided in his books and seminars on quality control. They are plotted on Levey–Jennings charts, wherein the X-axis shows each individual sample, and the Y-axis shows how much each one differs from the mean in terms of standard deviation (SD). The rules are: Review date: 1 April 2020 The recommended consequences when any of the above patterns occur is to reject the run, except for the rule of 12s (top in table), which serves as a warning and a recommendation of careful inspection of the data. See also * Western Electric rules *Nelson rules Nelson rules are a method in process control of determining whe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nelson Rules
Nelson rules are a method in process control of determining whether some measured variable is out of control (unpredictable versus consistent). Rules for detecting "out-of-control" or non-random conditions were first postulated by Walter A. Shewhart in the 1920s. The Nelson rules were first published in the October 1984 issue of the ''Journal of Quality Technology'' in an article by Lloyd S Nelson.Lloyd S. Nelson, "The Shewhart Control Chart—Tests for Special Causes". Journal of Quality Technology 16, no. 4 (October 1984), 238-239. https://doi.org/10.1080/00224065.1984.11978921 The rules are applied to a control chart on which the magnitude of some variable is plotted against time. The rules are based on the mean value and the standard deviation In statistics, the standard deviation is a measure of the amount of variation or dispersion of a set of values. A low standard deviation indicates that the values tend to be close to the mean (also called the expected value) of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autocorrelation
Autocorrelation, sometimes known as serial correlation in the discrete time case, is the correlation of a signal with a delayed copy of itself as a function of delay. Informally, it is the similarity between observations of a random variable as a function of the time lag between them. The analysis of autocorrelation is a mathematical tool for finding repeating patterns, such as the presence of a periodic signal obscured by noise, or identifying the missing fundamental frequency in a signal implied by its harmonic frequencies. It is often used in signal processing for analyzing functions or series of values, such as time domain signals. Different fields of study define autocorrelation differently, and not all of these definitions are equivalent. In some fields, the term is used interchangeably with autocovariance. Unit root processes, trend-stationary processes, autoregressive processes, and moving average processes are specific forms of processes with autocorrelatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skewed
In probability theory and statistics, skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean. The skewness value can be positive, zero, negative, or undefined. For a unimodal distribution, negative skew commonly indicates that the ''tail'' is on the left side of the distribution, and positive skew indicates that the tail is on the right. In cases where one tail is long but the other tail is fat, skewness does not obey a simple rule. For example, a zero value means that the tails on both sides of the mean balance out overall; this is the case for a symmetric distribution, but can also be true for an asymmetric distribution where one tail is long and thin, and the other is short but fat. Introduction Consider the two distributions in the figure just below. Within each graph, the values on the right side of the distribution taper differently from the values on the left side. These tapering sides are called ''t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Technometrics
Technometrics is a journal of statistics for the physical, chemical, and engineering sciences, published quarterly since 1959 by the American Society for Quality and the American Statistical Association. Statement of purpose The purpose of ''Technometrics'' is to contribute to the development and use of statistical methods in physical, chemical, and engineering sciences as well as information sciences and technology. This vision includes developments on the interface of statistics and computer science such as data mining, machine learning, large databases, and so on. The journal places a premium on clear communication among statisticians and practitioners of these sciences and an emphasis on the application of statistical concepts and methods to problems that occur in these fields. The journal will publish papers describing new statistical techniques, papers illustrating innovative application of known statistical methods, expository papers on particular statistical methods, and pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
False Positive
A false positive is an error in binary classification in which a test result incorrectly indicates the presence of a condition (such as a disease when the disease is not present), while a false negative is the opposite error, where the test result incorrectly indicates the absence of a condition when it is actually present. These are the two kinds of errors in a binary test, in contrast to the two kinds of correct result (a and a ). They are also known in medicine as a false positive (or false negative) diagnosis, and in statistical classification as a false positive (or false negative) error. In statistical hypothesis testing the analogous concepts are known as type I and type II errors, where a positive result corresponds to rejecting the null hypothesis, and a negative result corresponds to not rejecting the null hypothesis. The terms are often used interchangeably, but there are differences in detail and interpretation due to the differences between medical testing and stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rule 4 - Western Electric Control Chart
Rule or ruling may refer to: Education * Royal University of Law and Economics (RULE), a university in Cambodia Human activity * The exercise of political or personal control by someone with authority or power * Business rule, a rule pertaining to the structure or behavior internal to a business * School rule, a rule that is part of school discipline * Sport rule, a rule that defines how a sport is played * Game rule, a rule that defines how a game is played * Moral, a rule or element of a moral code for guiding choices in human behavior * Norm (philosophy), a kind of sentence or a reason to act, feel or believe * Rule of thumb, a principle with broad application that is not intended to be strictly accurate or reliable for every situation * Unspoken rule, an assumed rule of human behavior that is not voiced or written down * Slide rule, a mechanical analog computer Science * Rule of inference or transformation rule, a term in logic for a function which takes premis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rule 3 - Western Electric Control Chart
Rule or ruling may refer to: Education * Royal University of Law and Economics (RULE), a university in Cambodia Human activity * The exercise of political or personal control by someone with authority or power * Business rule, a rule pertaining to the structure or behavior internal to a business * School rule, a rule that is part of school discipline * Sport rule, a rule that defines how a sport is played * Game rule, a rule that defines how a game is played * Moral, a rule or element of a moral code for guiding choices in human behavior * Norm (philosophy), a kind of sentence or a reason to act, feel or believe * Rule of thumb, a principle with broad application that is not intended to be strictly accurate or reliable for every situation * Unspoken rule, an assumed rule of human behavior that is not voiced or written down * Slide rule, a mechanical analog computer Science * Rule of inference or transformation rule, a term in logic for a function which takes premi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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