Configuring the Factors

After setting the technique, you use the Factors subtab to select input parameters to select as factors to study and to define the attributes for each factor. The attributes are determined by the technique you selected.

There are three options when setting factor information: control, noise, and signal. Factors can be defined as both control and noise at the same time. The simultaneous control/noise assignment is necessary when a noise effect (parameter variation) cannot be separated from a design parameter (Control) nominal setting. For example, in a shape optimization problem that has a sizing parameter as a design variable you may want to introduce geometric tolerance as a noise factor. In that case the tolerances are not independent from the nominal design, and they should be entered as a relative value (for example, +/–0.001). Only one input can be selected as the signal factor. The input selected as the signal factor cannot be selected as a control or noise factor.

Once you select a factor, it appears on the P-Diagram tab.

  1. Double-click the Taguchi Robust Design component icon .
    The Taguchi Robust Design Component Editor appears.
  2. From the Taguchi Robust Design Component Editor, click the Control, Noise, or Signal tab.
  3. Click the Factors subtab.
  4. Right-click in the table to access various options for working with factors. For more information, see Setting Table Options.
  5. In the first column, click the check boxes next to the parameters that you want to use as factors.

    Alternatively, you can click Check to add all the selected parameters. To clear all parameters, click Uncheck.

    If no parameters are selected, you will be prompted to add all parameters as factors.

    Note: You can select only one signal factor. Therefore, on the Signal subtab there are no Check/Uncheck all buttons.

  6. Change any of the default values, which are provided for all attributes for a selected factor.

    Note: Depending on the technique, a change in one of the columns might automatically update any other related columns.

    Although each technique defines the appropriate set of attributes for a factor, the following attributes are common among many of the techniques:

    OptionDescription
    # Levels This attribute is the number of levels at which you want to study the factors. A change to this attribute automatically readjusts the levels for this factor.
    Levels This attribute is a space-separated list of the levels at which to study the factor. The related attributes are updated once you click in a different cell.
    Lower/Upper These attributes are lower/upper levels for the factor. A change to one of these attributes automatically calculates new levels evenly distributed between the lower and upper values.
    Relation This attribute specifies whether the levels are interpreted as values or as %/difference (diff.) from a specified baseline.
    Baseline This attribute is the value to be used for converting levels into values when the relation is “%” or “diff”. By default, this attribute is set to the current parameter value.

    Other factor attributes specific to individual techniques can be found in Configuring the DOE Component.

  7. (Dynamic-Standardized Systems only). On the Noise tab, determine the Standardized S/N Noise Approach setting:
    OptionDescription
    Noise Matrix (the default option) If you select Noise Matrix, the noise factors are defined exactly as defined in Configuring the Factors—factor attributes available are based on the noise technique selected.
    3 Noise Condition (negative side, reference, positive side) If you select 3 Noise Condition, the Technique and Matrix subtabs under the Noise tab are removed—no technique is selected for the noise factors and no matrix is generated. In this case, three noise experiments are fully defined in the noise factors table based on a specified negative noise condition, a reference noise condition, and a positive noise condition. The noise condition refers to the overall combined effect of the noise factors at each condition on the response values. The negative and positive side noise conditions can be defined relative to the reference condition using the relation attribute, by setting this attribute to % or diff.

    For more information about the 3 Noise Condition option, see Taguchi Dynamic-Standardized Analysis.

  8. If desired, click Edit at the bottom of the editor to set factor attributes for one or multiple factors. For more information, see Editing Attributes for Multiple Parameters.
  9. If desired, map these settings to parameters. For more information, see Mapping Options and Attributes to Parameters.
  10. Select Update factor baselines to current values when executing at the bottom of the tab if you want the baseline values updated to the current parameter values before executing.

    If Isight previously modified a parameter, this option allows for automatic updating of the baseline of all factors to the current parameter values in Isight, prior to executing the DOE technique, which will readjust the values to be studied appropriately. By default, this option is deactivated, which retains the user-defined settings. This option is useful if the DOE technique is executed after another element of the simulation process flow that might change the parameter values (for example, after an Optimization component), so that the DOE study can be performed around the new design point.

  11. Click OK to save your changes and to close the Taguchi Robust Design Component Editor.