Model-Driven and Software Product Line Engineering - Model-Driven and Software Product Line Engineering - page 111

4.5.1. Metamodels
Since we use a multi-staged approach for configuration and
derivation of products, we separate domain-specific concepts
in several metamodels. To create the product line of Smart-
Home systems, the first metamodel we build is the domain
metamodel, which serves as a vocabulary that is familiar to
the practitioners of the system's domain. A domain model
does not include concepts regarding details of the structure or
processing of the system. Other metamodels contain facilities
and architectural concepts, which are orthogonal to the
concepts in the domain metamodel. These concepts represent
variability that affects multiple domain concepts and their
subsequent processing (i.e. transformation and generation)
stages.
Each metamodel has a main objective to capture the
variability that characterizes a product line; however, they
play different roles during the product line development
lifecycle. Product designers use the first metamodel, the
domain metamodel, during the configuration process. This
metamodel is the reference to create domain models,which are
the starting point to derive product line members.
We create four metamodels to capture, separately, the
three sources of variability that characterize our Smart-Home
system's product line (see Chapter 2):
- Domain metamodel. This metamodel includes concepts
regarding architectural structure of houses.
- Smart-Home's facilities metamodel. Each house may
be equipped with several facilities related to controlled
devices.
- Components metamodel. This metamodel includes only
concepts concerning component-based development. This
metamodel is important to represent the problem domain in
terms of software components.