The technological advance as well as needs of human beings made that systems became more and more complex. In contrast, the use and creation of new modelling languages became simple and no more reserved for a handful of language experts. Consequently, many new practices of systems implementation emerged, among them, the use of different domain specific modelling languages (DSMLs) to represent the same system. Indeed, complex systems are composed by many components sometimes belonging to various domains. Thus, many teams of experts collaborate to develop such systems. Moreover, teams tend to use different DSMLs to design their concerns. This new practice generates an accidental heterogeneity due to production of various heterogeneous models representing a same system. However, those heterogeneous models need absolutely to be coordinated to facilitate communication between stakeholders and of course to ease implementation and validation of systems. This paper proposes a composition interfacebased approach to coordinate and integrate heterogeneous DSMLs in order to coordinate their models. The proposed composition interface is defined according to Bridge Design Pattern. To illustrate this approach two DSMLs are used: An Indoor Service Transport Modelling Language and an Internet of Things Modelling Language.