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30,000-foot-level Full of Problems OR Paradigm Shift?

I am writing this response as author of the <ahref=”https://www.smartersolutions.com/articles.htm”>November 2006 3.4 per million article, which generated QP Mailbag feedback in the January and February issues of Quality Progress. My response to Tim Folkerts’ comments in the January 2007 issue had been given in the discussion board. In this response I stated: The point relative

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Enhanced Control Charts for Variable Data with Predictive Process Capability Statement

This paper addresses x-bar and R control charting issues. For a given process, do you believe that everyone would make the same statement relative to: 1. process control/predictability from a created control chart? 2. process capability to meet its specifications? Not necessarily! Process statements such as these are not only a function of process characteristics but can also be very dependent upon sampling approach. The limits for the x-bar chart are derived from within-subgroup variability, while sampling standard deviation for XmR charts are calculated from between-subgroup variability. Statistical Process Control (SPC) has a primary purpose, which is to identify when special cause conditions occur for timely corrective actions. SPC textbooks and training state that an x-bar and R control chart is appropriate for situations where there are multiple continuous responses in a subgroup. Described in this paper are technical issues with the x-bar and R chart which can lead to falsely identifying common cause process variation as though it were special cause. The reason for these issues is discussed along with an alternative 30,000-foot-level reporting system that addresses these issues. Traditional x-bar and R control charts can lead to much firefighting, since the underlying assumptions for these charts are often not valid in the real world. In the 30,000-foot-level metric reporting methodology, which centers on use of the individuals control chart, process response is evaluated for regions of stability. Within identified stable regions, a process capability non-conformance estimate can then be reported. If there is a recent region of stability, one can consider the data in this region to be a random sample of the future; hence, a prediction statement can be made. Within identified stable regions, a process capability non-conformance estimate can then be reported if a specification exists. If there is a recent region of stability, one can consider the data in this region to be a random sample of the future; hence, a prediction statement can be made. An enterprise can assess its value-chain metrics collectively – where each has 30,000-foot-level reporting – to determine where improvements can be made that positively impact the enterprise financials as a whole. Goals to these metrics would pull for a process improvement or design project creation that positively impacts these 30,000-foot-level metrics.

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Reference: upcoming article for Engineers Digest

Breyfogle states “Design of Experiments (DOE), sometimes called Multivariable Testing (MVT), and other statistical tools can be very beneficial within organizations, if these tools are implemented wisely. We have found DOE to be a particular useful tool in both Design, Manufacturing, and Service/Transactional environments, since someone can address a very large number of factors within

Reference: upcoming article for Engineers Digest Read More »