Glass transition theory based on stress relaxation
  We propose that an onset of glass transition can be defined as the point at which a supercooled liquid acquires the stress relaxation mechanism of a solid glass. We translate this condition into the rate equation for local relaxation events. This equation simultaneously gives two main signatures of glass transition, stretched-exponential relaxation and the Vogel-Fulcher law. The proposed theory quantifies system fragility in terms of the number of retarded local relaxation events and reproduces its correlation with the non-exponentiality of relaxation and bonding type. 
Kostya Trachenko