Software Product Line Engineering Basics - Model-Driven and Software Product Line Engineering - page 45

2.7.2. Product derivation
D EFINITION 2.10.- The product derivation is the activity related
to the manual or automated construction of product line
members from the product configuration, the core asset, and the
production plan.
The requirement specifications of products, which are
captured in product configurations, are the main input for the
product derivation activity. Therefore, to derive products, it is
necessary to adapt and assemble core assets according to the
variants chosen from the variability models and captured in
product configurations. The guidelines and rules to build the
correctproductfromaproductconfigurationandthecoreassets
are defined in the production plan. As already mentioned, the
production plan refers to a reference architecture, which is the
general map to construct the products.
Core assets are, thus, the re-usable artifacts considered
as building blocks; these artifacts include re-usable common
models, components, documentation, requirements, and test
cases among others. Product line architects create core assets
according to the variants identified and documented during
the activity of variability management. For instance, for the
Expiration feature from Figure 2.6, a product line architect
creates two (different) software components, one for each
group, inDays and Never . The first software component has
services for checking that passwords are changed once in a
specified number of days, and for supporting the requirement
of changing a password.This software component is created for
the inDays feature. The second software component, created
for the Never feature, only has one service to inform that
passwords cannot be changed.
Inpractice,thereisasignificantgapbetweenvariabilityata
conceptual level (variation points and variants) and variability
at the implementation level (concrete core assets). Decision
models [ATK 00, BAY 00, FOR 08, DHU 08] intend to close