Creo Simulate > Getting Started with Creo Simulate > Planning and Modeling Considerations > Planning for Optimization > Optimization and Assemblies
  
Optimization and Assemblies
If you optimize an assembly part, the changes that Creo Simulate makes during optimization may result in a part that no longer fits the assembly.
In most cases, these changes will be obvious when you preview your design variables by animating the part's shape. Subtle changes, however, may be more difficult to catch. Fit problems may be even less obvious if you suppressed any features to better accommodate a sensitivity study or optimization.
As you prepare your part for use with Creo Simulate, be aware of which features and dimensions are critical in the context of the assembly. Determine whether the benefits of using such a feature or dimension in the optimization outweigh the cost of changing an entire assembly. Where possible, avoid creating design variables for these features and dimensions.
Return to Optimization Planning.