Abstract
Investigations proceed as an iterative and recursive learning process, involving a sequence of experiments. Evaluating the results from a prior set of experiments allows the investigator to design and predict the next experimental cycle better. The investigator looks at what has gone before with a view to improve and extend the inquiry. This communication reiterates the value of sequential experimentation in product development. A fluid-bed granulation study is used to illustrate the sequential approach. Acceptable solutions were achieved using technical knowledge, a sequence of factorial designs, and graphical data analysis.