Reliable Shewhart-type Control Charts for Multivariate Process Variability

In manufacturing industry, data collection is expensive and time consuming. Therefore, to monitor the quality of production process, the use of small sample is strongly required. Unfortunately, the current techniques of multivariate process variability monitoring for small sample are developed based on heuristic approach. As a consequence, their reliability is unknown. This book introduces a reliable version of GV-Chart (the most adopted technique) and a reliable version of VV-Chart. Since both charts are complementary to each other, their simultaneous use is recommended. Furthermore, for practical purposes, the book is completed with statistical tables of reliability constant for some selected sample sizes and selected number of quality characteristics. Real industrial applications are also provided to illustrate the advantages of the two reliable charts.