In quality control, multi-vari charts are a visual way of presenting variability through a series of charts. The content and format of the charts has evolved over time.
Original concept
Multi-vari charts were first described by Leonard Seder in 1950,[1][2] though they were developed independently by multiple sources. They were inspired by the stock market candlestick charts or open-high-low-close charts.[3]
The quality characteristic of interest is measured at two extremes (around its diameter, along its length, or across its surface) and these measurements are plotted as vertical lines connecting the minimum and maximum values over time.
The quality characteristic of interest is plotted across three horizontal panels that represent:
Variability on a single piece
Piece-to-piece variability
Time-to-time variability
The quality characteristic of interest is plotted against upper and lower specifications rather than control limits.
Examine process inputs or steps for evidence of shifts or drifts
Recent usage
More recently, the term "multi-vari chart" has been used to describe a visual way to display analysis of variance data (typically be expressed in tabular format).[5] It consists of a series of panels which portray minimum, mean, and maximum responses for each treatment combination of interest rather than for periods of time.
Because it is a two-dimensional representation of multiple dimensions (one for each factor in the ANOVA), the multi-vari chart is only useful for comparing the variability among at most four factors.
The chart consists of the following:
One horizontal panel for each level of the outermost factor
One cluster of points representing the minimum, mean, and maximum responses for the particular treatment combination, connected by lines for each level of the innermost factor
In the case of four factors, vertical panels for each level of the next-innermost factor
As with control charts, the vertical axis depicts the quality characteristic of interest (or experimental response)
multi, vari, chart, quality, control, multi, vari, charts, visual, presenting, variability, through, series, charts, content, format, charts, evolved, over, time, original, concept, edits, were, first, described, leonard, seder, 1950, though, they, were, devel. In quality control multi vari charts are a visual way of presenting variability through a series of charts The content and format of the charts has evolved over time Original concept EditMulti vari charts were first described by Leonard Seder in 1950 1 2 though they were developed independently by multiple sources They were inspired by the stock market candlestick charts or open high low close charts 3 As originally conceived the multi vari chart resembles a Shewhart individuals control chart with the following differences The quality characteristic of interest is measured at two extremes around its diameter along its length or across its surface and these measurements are plotted as vertical lines connecting the minimum and maximum values over time The quality characteristic of interest is plotted across three horizontal panels that represent Variability on a single piece Piece to piece variability Time to time variabilityThe quality characteristic of interest is plotted against upper and lower specifications rather than control limits The three panels are interpreted as follows 4 Panel Condition Corrective actionVariability on a single piece Lengths of the vertical lines i e the range exceed one half the specifications or more Repair or realignment of toolPiece to piece variability Excessive scatter Examine process inputs for excessive variability lengths of the vertical lines are estimates of process capabilityTime to time variability Appearance of a non stationary process Examine process inputs or steps for evidence of shifts or driftsRecent usage EditMore recently the term multi vari chart has been used to describe a visual way to display analysis of variance data typically be expressed in tabular format 5 It consists of a series of panels which portray minimum mean and maximum responses for each treatment combination of interest rather than for periods of time Because it is a two dimensional representation of multiple dimensions one for each factor in the ANOVA the multi vari chart is only useful for comparing the variability among at most four factors The chart consists of the following One horizontal panel for each level of the outermost factor One cluster of points representing the minimum mean and maximum responses for the particular treatment combination connected by lines for each level of the innermost factor In the case of four factors vertical panels for each level of the next innermost factor As with control charts the vertical axis depicts the quality characteristic of interest or experimental response References Edit Seder Leonard 1950 Diagnosis with Diagrams Part I Industrial Quality Control New York New York American Society for Quality Control vol 7 no 1 pp 11 19 Seder Leonard 1950 Diagnosis with Diagrams Part II Industrial Quality Control New York New York American Society for Quality Control vol 7 no 2 pp 7 11 Juran Joseph M 1962 Quality Control Handbook 2 ed New York New York McGraw Hill pp 11 30 Juran Joseph M 1962 Quality Control Handbook 2 ed New York New York McGraw Hill pp 11 30 11 31 Tague Nancy R 1995 The Quality Toolbox 2 ed Milwaukee Wisconsin American Society for Quality Control pp 356 359 Retrieved from https en wikipedia org w index php title Multi vari chart amp oldid 768958444, wikipedia, wiki, book, books, library,
