Comparison of 3D CAD model is required to retrieve 3D design from CAD model database for design reuse,
mass customization and machining process planning. Typical CAD model retrieval systems are based on part
names, codes or annotations assigned to 3D CAD models. However, aforementioned approaches have
limitations on usability and robustness of retrieval results. In this research, we proposed the approach of
comparing 3D CAD models by improving global descriptor based shape comparison methods. Our proposed
method can be applied to assembly models. By deriving separate measurement values for part shape
dissimilarity and assembly relationship dissimilarity, detailed comparison result can be obtained compared
with existing 3D shape comparison methods.