Despite the growing popularity of digital twin (DT) developments, there
is a lack of common understanding and fundamental definition of DT. This
issue creates even more challenges in evaluating the applicability and maturity of existing DT frameworks. A shared understanding of DT based on unambiguous characterization is required to be developed to mitigate the
challenge of both research and commercial communications. With these in
mind, the objective of our study is to assess the existing DT models from
various domains to unify the knowledge and understanding of DT developers
and stakeholders. We conducted a systematic literature review and analyzed
25 selected papers out of 107 to identify and discuss the characteristics of
existing DTs. The review shows an inconsistency in the characterisation of
the existing DT models, mostly influenced by case-specific focus of the devel-
opers. Therefore, this article proposes a three-phase evaluation framework
to assess the maturity of digital twins across different domains, focusing on
the characteristics of digital models. The four identified dimensions in this
model are Capability, Cooperability, Comprehensiveness, andLifecycle. Based
on that, a maturity score is calculated with a implemented weight mechanism
to adapt the importance of each dimension for different application require-
ments. Several case studies are devised to validate the proposed model in
general, industrial and scientific cases