A theory of local dynamics of liquid is developed in order to explain the glass transition and fragility of multi-component alloys as it relates to formation of bulk metallic glasses. Unlike the extended hydrodynamic theories in which liquid is regarded as a continuum body, the present approach focuses on the discreteness of the atomic structure and considers the stability of local topology of the network structure. This approach has led to the prediction of the glass transition temperature, melting and glass formability. We extend this approach to describe the effects of local topology on the atomic transport and glass transition and fragility of multi-component glasses. This theory leads to a picture of a strong liquid as a nano-scale composite of glass and liquid, and suggests compositional requirements for forming bulk metallic glasses.