Using Design of Experiments (DOE) Techniques to Avoid Process Problems

ABSTRACT

Typically, process validation consists of a well-rehearsed demonstration that the manufacturing formula can work three successive times. The manufacturing process being demonstrated during validation consists of a set of specifically chosen operating parameters being employed to create a finished product with desired attributes. Because of this, traditional validation does not communicate an understanding of the specific relationships between all of the independent variables (process variation) and the dependent variables (variation in finished product quality). It is the authors' experience that this type of validation exercise precedes a trouble-free time period in the manufacturing area only to be followed by many hours (possibly days or weeks) of troubleshooting and experimental work after a batch or two of product fails to meet specification. This becomes a never-ending task.