BIS.Net Team
Shewhart, the recognized founder of statistical process control specified two stages for SPC. The first stage is about the initial establishment of the process.
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Dr Juergen Ude
Taguchi’s loss function has no sound mathematical basis, it was derived by simply arbitrarily truncating Taylor’s theorem at a mathematically convenient point.
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Dr Juergen Ude
If we really wish to make competitive improvements, we will need to go beyond slavish adherence to methodologies developed in the 1920s. Many statistical methodologies of the ‘twenties’ were based on assumptions no longer appropriate in an age of readily available computer power.
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Dr Juergen Ude
If the sample size is small a popular option is to calculate a confidence interval using sample information. If the confidence interval covers the reference value, then the null hypothesis is accepted.
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Dr Juergen Ude
This article discusses how the use of sub-groups can lead to exceedingly wide control limits, reducing the effectiveness of control charts, leading to loss of credibility. The x-bar chart will be used to demonstrate the problem.
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Dr Juergen Ude
The quality movement seems to agree that it is wastefully to inspect quality into the product, after it is manufactured, instead of getting-it-right-first. As we are advancing towards the twenty first century it is appropriate to ask whether we really have advanced from the old way of doing things.
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Dr Juergen Ude
For effective process control we need a control chart which is sufficiently sensitive to rapidly detect a change in the process average, whilst rarely giving false alarm signals. A measure of sensitivity is the average run length (ARL).
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Dr Juergen Ude
This article discusses the various problems that may occur through direct text-book application of statistical process control chart theory. SPC is currently receiving considerable attention by industry to improve quality and productivity.
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