PROCESS CONTROL USING MULTIVARIATE ANALYSIS: UNDERGRADUATE RESEARCH EXPERIENCE THROUGH PRACTICAL CASES

Abstract

In this paper, the importance of
multivariate quality control has been discussed, when it is
desired to exercise process control on products that present
two or more measurable characteristics which can suffer
variations and on the other hand are considered significant
for the functioning or the acceptance of the product. As
undergraduate research experience, students used
multivariate T2 control charts to control two and three
dependent variables that were present in a mechanical
manufacturing component and in a soft drink production
process respectively. These multivariate control charts
provided better insight in detecting out of control states than
that of Shewhart control charts. The practical cases gave
opportunities for the student teams to learn the usefulness of
advanced statistical models, collect data in the industrial
environment, analyze and interpret data using appropriate
statistical software packages, as well as draw useful
conclusions on the production processes studied and
analyzed.

Index Terms ⎯ Process control, quality characteristics,
dependent variables, Shewhart control charts, and
multivariate T2 control charts.