Chemometrics - A holistic approach to troubleshooting,
M.J.McCann & C.A.Bishop, Proc. 42nd Annual Technical Conference, Society of Vacuum Coaters, Chicago, USA, April 1999.

This paper is copyright by the SVC, from whom copies can be obtained. Only the ABSTRACT is shown here. Dr Bishop can be contacted by email directly, or through me.

Abstract.
It is common when troubleshooting to isolate the problem area and to look at that area in great depth. This is particularly true for complex processes.

However, this can mean that interactions that are distanced from each other within the whole process are missed. The data used can include information on parts of the process that might normally not be included. If there is more than one supplier of raw materials, this information can be incorporated, as too could be data from an earlier wet coating process. Thus, this technique can be regarded as truly holistic in nature.

The use of chemometrics or multivariate analysis as data mining tools enables the whole process to be analysed at once. Using tools such as hierarchical cluster analysis and principal components analysis enable interactions to be identified and, if necessary, tested. This technique can be used on production processes, it is not exclusive to research, and it is not intrusive so that it is not disruptive to production.

Background.
We showed, using Piroutte software (Chemometrics) to look at data with hidden correlations buried in it, without them necessarily having any apparent causal link. We were able to show the way in which the cluster analysis, principal components analysis etc identified the places where the couplings were present, though there really wasn't enough data to get all the correlations out by normal statistical means.
There are other tools readily available to do such work, including the "R" software which is openly available for anyone to use. McCann has exploited it in banking and risk analyis questions.

Help is near at hand....
    If you want help with troubleshooting on a process, particularly, but not confined to web coating, we will be happy to help. Contact us.