Software Product Line Engineering Basics - Model-Driven and Software Product Line Engineering - page 49

2.9.1. Variability management
At present, there is no standard way to represent variation
points and variants in variability models. However, one of the
most used methods to represent variation points and variants
is by means of feature models. Feature modeling and meta
modeling deserve special attention in this topic. Currently,
in SPL engineering, there is a trend to separate different
concerns involved in a product line. For example,it is desirable
to create a variability model including software design
concerns separately from technological platform concerns.
This separation of concerns facilitates the product line
architects' tasks focusing on particular concerns at different
times. Similarly, when products are configured, staged feature
configurations could be created by different groups of product
designers focusing on particular concerns. To facilitate the
separationofconcernsandthestagedconfigurationofproducts,
separate feature models can be created. Czarnecki et al .
motivate the concept of staged configuration and stepwise
specialization of feature models [CZA 05]. They propose to
create separate feature models but with relationships between
them. Thus, they avoid a breakdown between the different
concerns of individual feature models. For instance,they create
a feature model including software architectural concerns
and another feature model including technological platform
concerns. They maintain relationships between these feature
models. For example, one relationship indicates that only
if the feature ObservablePattern of the architectural feature
model appears in a feature configuration, then the feature
OSGi-PeriodicComponent of the platform feature model will
be available to be selected. In Chapter 4, we present how we
have introduced the concept of staged expression of variability
and staged configuration of products in our MD-SPL approach.
2.9.2. Product derivation
Product derivation is the process of building a product
from its configuration and according to the production plan.