FEMGEN is the pre-processing part of the program where two or three dimensional geometric models of an item, component or structure are created using points, lines, surfaces and bodies as required.

A finite element mesh is created from the geometric model and can be modified and refined until a suitable mesh is produced. The additional information needed for an analysis such as material data, boundary conditions, loading etc is associated with the geometric model and is unaffected by changes to the mesh itself. The specification of this information is made easy by the use of sets.