Sheet metal forming processes are largely used in mechanical manufacturing processes. In sheet metal studies the localized necking and formability are very important. Therefore, for industrials, numerical tools are necessary in order to quantify the formability of sheets as well as a deep understanding of the mechanism of necking. The forming limit diagram (FLD) and finite element method (FEM) are used for predicting these design parameters. For localization necking, several criteria are developed such as the M-K model, Swift model, etc. These analytical models are divided into three different models: The bifurcation theory, continuum damage mechanics and geometrical imperfection model. The M-K model is in the geometrical imperfection model category. The FLD is used for predicting the formability of different metals. The FLD is calculated from the different mechanical tests such as the biaxial traction test or Nakazima drawing test. The nakazima test is an experimental process for predicting the FLD for different metals. The formability of metals depends on several parameters. The formability of metals can be increased by changing these parameters. Several studies are done to predict or increasing the metals alloy’s formability.