feasible region
The area formed by the two variables displayed on the X- and Y-axes such that the response values fall between their lower and upper bounds. Any settings for the two plotted variables in the feasible region, while keeping all other variables fixed, should produce a product with acceptable responses.
For designs with more than two continuous variables, Minitab displays the hold values at the bottom right of the plot.
Free online chart generators for statistical analysis:
Useful tools: