Process characterization

Studies done before commercial manufacturing to map how process parameters affect quality attributes and process performance, usually in qualified scale-down models, guided by risk assessment and design of experiments. The results classify parameters as critical or not, set proven acceptable ranges and form the basis of the control strategy that process validation then confirms. Japanese documents use this term and a loanword for characterization. Weak characterization usually shows up later, as deviations at commercial scale that nobody can explain.