Statistical quality control of multivariable continuous processes

Multivariate statistical methods are utilized for developing statistical quality control techniques for multivariable continuous processes. The performance of univariate Shewhart charts, Hotelling´s T² combined with univariate Shewhart charts, residuals based SPC techniques, and parameter based SPC techniques are compared. Control of mean droplet size and droplet size distribution in a spray drying process are utilized to illustrate the techniques discussed.