In plastic thermoforming, the thickness of the finished part  varies, getting thinner generally from top to bottom.  I want to know if someone has an efficient way to simulate this thinning in a model.  I have tried move face and offset surfaces.  While these work, they become impractical for more complex parts. I have enclosed a simple model with a small thinning factor applied.  In this case, it is the max that the move face function will allow.