The introduction of isoparametric elements into the finite element method (FEM) of structural analysis substantially reduced the number of elements needed to describe complex shapes. For simple geometric shapes, it is now possible to use automatic mesh-generation routines to speed model building. A row of elements is defined by the analyst, and then the computer sweeps this mesh across the whole structure. The major advancement in FEM is the ability to combine in models the data from both empirical tests and analytical methods.