Overview for Define Custom Mixture Design

Use Define Custom Mixture Design to create a design from data you already have in the worksheet. You can specify which columns contain your components and other design characteristics, such as process variables. You can also specify constraints for the components.

Mixture experiments include response variables that depend on the relative proportions of mixture components, such as the ingredients in bread dough. Minitab provides three design types, including simplex centroid, simplex lattice, and extreme vertices designs. You can also include process variables and total amounts of the mixture. For more information, go to What is a mixture design? and Choose a mixture design.

Usually, you define a custom design for one of the following reasons:
  • You created a design in Minitab and modified the worksheet so that Minitab could no longer analyze the design. For example, Minitab cannot analyze the design if you move or delete the column that contains the standard order of the design.
  • You typed the design information directly into the worksheet.
  • You imported the design from a non-Minitab file.
  • You created the design using Minitab Session commands.
  • You created the design with a version of Minitab older than version 13.

For example, an engineer has a mixture design in a Microsoft Excel spreadsheet and wants to use Minitab to analyze the data. The engineer opens the worksheet in Minitab, defines the design as a custom mixture design, and then is able to use Minitab to analyze the design.

Where to find this analysis

Stat > DOE > Mixture > Define Custom Mixture Design