In this talk, I will talk about the issues on simplifying an engineering design model for efficient engieering analysis and report our recent progress on it. Practical engineering components usually contain many detail features, most of which have little impact on the final engineering analysis results, but the presence of these detail features will cause much computational burden in downstream task such as volume mesh generation and finite elements analysis. Thus, simplying a complex engieering component before performing engineering analysis on it is a typical approach in pratical engineering analysis. We see the core issue to fully resolving this open problem as a quantative measure to etimating the impact of estimating the engineering error caused by removing a set of features from a geometric model. We report our recent progress on this problem and other considerations on its future work.