Which statement is NOT true?

Most of the literature on profile monitoring deals with phase II analysis of linear profiles.

Profiles occur when a critical$-$to$-$quality characteristic is functionally dependent on one or more explanatory or independent variables.

Shewhart control charts and EWMA and CUSUM control charts have limited use among in the practice of assignable causes that result in changes in the process input.

Control charts are used to monitor processes looking for assignable causes that result in changes in the process output.

All statements are true.