Data - Response Optimizer
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You must fit a factorial design model before you can use the response optimizer. Response optimizer does not use the data in the worksheet. Instead, Minitab looks in the worksheet for a stored model(s) to obtain the necessary information.

You can fit a model with different variables for each response. However, a variable in one model cannot be the response in another model. If a variable was not included in the model for a particular response, the optimization plot for that response-variable combination shows no change in the response when the variable changes.

Minitab automatically stores the most recent model that you fit for each response variable. To view information about models that are stored in the worksheet, click View Model in the Response Optimizer dialog.