Quality Assurance in the Presence of Variability - Intentional Perspectives on Information Systems Engineering - page 314

current research interests include software product lines, respectively variability in
process lines. Her interest and her valuable contributions to this relatively new field
of research [ 24, 25] is yet another indication that Colette Rolland is a very active,
inspiring and trendsetting researcher - even after having reached the retirement.
Software Product Line Engineering (SPLE) is a reuse-driven development
paradigm that has been applied successfully in information system engineering [ 25] ,
business process modeling [24] and other domains [ 19] . SPLE explicitly addresses
reuse by differentiating between two kinds of development processes [19] :

•

Domain engineering : During this process, the commonality and the variabil-
ity of the product line is defined. Furthermore, the reusable artifacts, called
domain artifacts, are realized which implement the commonalities and provide
the variability required to derive the set of intended products. The domain arti-
facts include, among others, requirements models (e.g., use case diagrams),
architectural models (e.g., component or class diagrams) and test models.

• Application engineering : This process is responsible for deriving products from

the domain artifacts. Application engineering exploits the variability of the
domain artifacts by binding (or resolving) variability according to customer
and/or market-specific needs.

The central concept for addressing reuse in product line engineering is the defi-
nition of product line commonality and variability. Product line commonality refers
to parts or aspects of the product line that are part of all products of the product line.
Product line variability describes the possible variation between the products that
belong to a software product line in terms of properties and qualities [ 17, 19] .
Early quality assurance is an important issue in every development project. The
quality assurance of variability models has received great attention in product line
research [ 28] , whereas the comprehensive quality assurance of other artifacts (e.g.
requirements, design, or implementation artifacts) is still an open issue. The prod-
uct line variability constitutes a central challenge for quality assurance of domain
artifacts. Quality assurance techniques from single-system engineering cannot be
directly applied to domain artifacts, since the domain artifacts contain variability.
In this chapter, we first illustrate the effects of variability on the quality assurance
of domain artifacts (Sect. 2) . We will then present different strategies that have been
developed for the quality assurance of domain artifacts in the presence of variability
(Sect. 3) . For each strategy, we will discuss the benefits and the involved challenges.
We will then focus on a particular strategy, the so called comprehensive strat-
egy which aims at checking the quality of all possible products of the product line.
This strategy offers the highest benefits, since it uncovers the defects in all possi-
ble products. However, the central challenge for the comprehensive strategy is the
complexity that results from the product line variability and the large number of
potential products of a product line.
Since techniques from single system engineering are not applicable, the devel-
opment of new or adapted techniques is necessary. As an example for possible
adaptation, we will present a quality assurance approach for the comprehensive