Graphical simulation animation of a CAD system  can be  used to inspect the tolerance and interference of matching components of a product. It will be  possible to precisely define  these  values and produce better  product.
Flexibility  and Economy: CAD  efficiently  provides a document at each  design  step and offers  great flexibility and economy in the management of design data which include  all important  design information and product geometries. The use of CAD make s it possible both  to produce  good working drawings and the preserve  clearly the results of some of the computations involved in the design process. Also it is easier to edit drawings and correct mistakes  on the computer  than it  would be do so  manually. Further CAD  assists in coordinating among group  to share the  design  results and data.