1 January 1988 Dynamic Statistical Process Control
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Although some control techniques such as Shewhart and CUSUM Control Charts are not new, their application in industry for process control is relatively new. In recent years manufacturing industries have begun to discover and appreciate the power and efficiency of statistical process control techniques. These charts have been successfully used in some areas and have created confusion in others. The confusion is normally due to incorrect application of the methods and lack of sufficient understanding of the theory and assumptions underlying these charts. One of the important assumptions in using Shewhart and CUSUM charts is that the individual measurements are statistically independent. In many industrial situations this assumption is not valid. Namely, the measurements are correlated. As a result the application of the above techniques ends in incorrect conclusions and hence, confusion. The purpose of this paper is to discuss appropriate methods for dealing with these situations. Time series modeling will be discussed. It will be shown how the correlations in data can be used for more precisely predicting and controlling a process.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Rahman Azari, Rahman Azari, Fred Khorasani, Fred Khorasani, Cynthia Bickerstaff, Cynthia Bickerstaff, "Dynamic Statistical Process Control", Proc. SPIE 0921, Integrated Circuit Metrology, Inspection, and Process Control II, (1 January 1988); doi: 10.1117/12.968373; https://doi.org/10.1117/12.968373

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