  This paper aims to provide a comprehensive critical overview on how entities
and their interactions in Complex Networked Systems (CNS) are modelled across
disciplines as they approach their ultimate goal of creating a Digital Twin
(DT) that perfectly matches the reality. We propose a new framework to
conceptually compare diverse existing modelling paradigms from different
perspectives and create unified assessment criteria to assess their respective
capabilities of reaching such an ultimate goal. Using the proposed criteria, we
also appraise how far the reviewed current state-of-the-art approaches are from
the idealised DTs. We also identify and propose potential directions and ways
of building a DT-orientated CNS based on the convergence and integration of CNS
and DT utilising a variety of cross-disciplinary techniques.
