38 Cyber-Physical Systems: From Theory to Practice
for the construction of domain models through a collection of objects and connectors. GME ensures
that the domain-specific instance models comply with the specified metamodel. Within the meta-
model, there are different concepts to represent an object. An object can either be an atom, which is
the basic indivisible object that cannot contain other objects; a connection, which can connect two
objects; or a model, which can contain other objects such as atoms, connections, or models. Hier-
archical composition is supported through model elements. Within model elements, objects can be
connected to each other based on the rules defined in the metamodel. Each connection has a source
object (denoted by ...