| Summary: | 碩士 === 國立交通大學 === 統計學研究所 === 96 === Traditional control charting methods in statistical process control monitor the
quality characteristic of the product or process of interest directly. Now thanks
to well-developed technologies, we can easily record many other related data that
may provide additional information about the quality characteristic at different time
points. For example, we can record the quality response variable along the time
before the end product is finished. If we regard the record of these values as the
profile of a product item, then the quality characteristic of the end product is the
endpoint of the profile. It is natural to expect that this auxiliary information would
be able to help enhancing the control process.
In this study, we focus on Phase II monitoring. Our approach is to fit each
profile by parametric or nonparametric regression methods, and then monitor the
fitted endpoint value instead of the endpoint response. It can be shown that, with
the additional profiles information, the fitted endpoint response has smaller variance
than the endpoint response itself. Accordingly, when compared to the traditional
approach, better detecting power can be achieved with the proposed approach
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