Describe some of the productivity gains by CAD applications. Solution Designing of Three-Dimensional Models - CAD has made the process of designing and modifying 3D models a lot easier. Prior to CAD, it required the construction and direct manipulation of physical models. Now the models are created digitally with varying degrees of sophistication. Verification of the Design Models - Models are designed within certain specifications and CAD provides calculation tools to ensure the design meet those specifications. Saving of design data and drawings - All the data used for designing can easily be saved and used for future references, thus certain components don’t have to be designed again and again..