The stabilization of the amorphous solid with respect to the high temperature liquid phase is modeled thermodynamically as a second order phase transformation. The model proposed in this work incorporates the thermodynamic description of the high temperature liquid phase, the glass transition temperature, and the maximum entropy of amorphization in an explicit formalism. The predicted heat of formation of the amorphous solid in the Cu-Zr and Ni-Zr systems agrees well with experimentally determined data.