Local Sensitivity Study

A local sensitivity study calculates the effect of slight changes in one or more design variables on your model's measures. Creo Simulate calculates the slope of the sensitivity curve between two sample points. The result is a graph of the linear approximation of a measure over a variable's range. The sensitivity slopes are also reported in the run summary file.

Creo Simulate computes local sensitivity by first performing a base analysis followed by a perturbation analysis for each design variable. A base analysis is the same as a standard analysis. In a perturbation analysis, Creo Simulate changes the design variable by an incremental amount and then performs a new analysis.

Creo Simulate uses the results of the perturbation analysis and base analysis to compute a slope. This value is the same as the slope of the global sensitivity curve at a given value of the variables. By comparing the rates of change caused by several variables, you can determine which variables affect the model the most. The larger the rate of change, the greater the effect.

If you are using local sensitivity studies to facilitate future optimization runs, consider the strategies listed in Optimizing a Model when reviewing your sensitivity results.

You can use a local sensitivity study to determine the most important design variables for your model, which provides a way of reducing the number of variables used in global and optimization studies. This, in turn, reduces run times and resource requirements.

Creo Simulate calculates values for all measures that are valid for the analyses included in the study. But Creo Simulate does not calculate the value for measures using the At Each Step option when you use dynamic time, frequency, or random response analyses in a local sensitivity study.

The Sensitivity Study Definition dialog box contains the following items for local sensitivity:

• Analyses—Select one or more analyses from this list. Creo Simulate calculates and displays results separately for each analysis.

• Variables—Click or to select and add a dimension or a Creo Parametric parameter to the Variables table of your design study.