Getting Familiar with the Design of Experiments Window 

The Design of Experiments window enables you to perform virtual experiments taking into account as many parameters as needed. It can be accessed by clicking the Design of Experiments icon () in the Product Engineering Optimizer workbench.

The Design of Experiments Window is made up of three different tabs:

Settings tab 

This tab enables you to define the analysis to be performed. In this tab, you:

 
  • select the input parameters
 
  • select the ranges (field of study) to be applied as well as the number of levels (number of nodes)
 
  • select the output parameters 
 
  • run the Design of Experiments.

Select input parameters

This field enables you to select the input parameters that will be taken into account when performing the analysis.
Click to access the Select the input parameters window, click the parameters, use the button to select them, and click OK.
To remove parameters, click Edit list... and use the arrow button to remove them from the selected parameters and click OK.

Select an input parameter and click (or double-click the parameter) to specify the superior and the inferior ranges of the input parameter and to indicate the number of levels. The multiplication of these levels matches the number of updates performed (computed automatically).

Note that if you forget to check this option, and you do not want to re-run the DOE, you can generate DOE curves manually. For more information, see Useful Tips.

Select output parameters

This field enables you to select the output parameters (also called output factors) under consideration.

Click to access the Select the output parameters window, select one or more parameters by using the button and click OK.
To remove parameters, click Edit list... and use the arrow button to remove them from the selected parameters and click OK.

Note that the Filter Type scrolling list enables you to filter the type of output parameters.
 
  • Save curves in the output file: enables you to display curves in a .XLS file. (for Windows only)
 
  • enables you to launch the analysis. If you did not run the DOE before, you will be asked for an output file, else a contextual menu will be displayed depending on the action you performed before (full run, or interrupted run.)

Results tab

This tab is only available after the analysis is performed and is disabled if the information contained in the Settings tab are not up-to-date.

The matrix displayed in the Table of experiments section is the result of computations performed for each node: the number of evaluations presented matches the number of updates displayed in the Settings tab.

enables you to select a value in the matrix and to apply it to parameters.

 

Generated Curves

The number of curves generated depends on the number of selected input and output parameters. A curve is generated:

 
  • for each input and each output for the effects
 
  • for each couple of input factors and for each output.

Here are two curves samples (the data used to produce these curves are provided in the Using the Design of Experiments Tool topic.)

Plot of one factor effect on one output

This graphic shows the mean effect of the 'OxLength' parameter on the OxyPerimeter. (Click the graphic opposite to enlarge it.)

The three curves are parallel which means that there is no interaction between the OxLength and OyLength parameters on the output parameter (OxyParameter) (i.e. the effect of OxLength on OxPerimeter does not depend on the OyLength value.)

The yellow curve represents the mean. The red curve represents the mean plus 3 standard deviations. The green curve represents the mean minus 3 standard deviations. Statistically, for a given value of Ox, 99% of the values of the OXyPerimenter are located in the range between the green and the red dots.

Plot of interaction between 2 input factors on one output

This graphic shows the interaction effect of the "OxLength" and "OyLength" parameters on the OxyArea. (Click the graphic opposite to enlarge it.)

 

 

Prediction tab

This tab presents a mathematical model of the system and is used to get a theoretical value of the output parameter considering a specific configuration of the input parameters. 

 
If the result is not satisfying, refine your analysis by adding levels in the Settings tab.

You can choose one of the 2 alternatives below to obtain predictions:

Computing the theoretical value of a node:

 
  • Click the Results tab and select a row.
 
  • Click Apply values.
 
  • Click the Prediction tab and click Run prediction: the result is displayed in the lower pane of the window.

Computing the theoretical value of a node of the field of study (outside the network):

 
  • Click the parameter to select it.
 
  • Change its value in the Selected parameter value field (press Enter  or click anywhere to validate the input). Repeat this operation for each parameter you want to use.
 
  • Click Run prediction: the result is displayed in the lower pane of the window.