  Software engineers have adopted the Dynamic Software Product Lines (DSPL)
engineering practices to develop Dynamically Adaptable Software (DAS). DAS is
seen as a DSPL application and must cope with a large number of configurations
of features, Non-functional Requirements (NFRs), and contexts. However, the
accurate representation of the impact of features over NFRs and contexts for
the identification of optimal configurations is not a trivial task. Software
engineers need to have domain knowledge and design DAS before deploying to
satisfy those requirements. Aiming to handle them, we proposed an approach of
Trade-off Analysis for DSPL at design-time, named ToffA-DSPL. It deals with the
configuration selection process considering interactions between NFRs and
contexts. We performed an exploratory study based on simulations to identify
the usefulness of the ToffA-DSPL approach. In general, the configurations
suggested by ToffA-DSPL provide high satisfaction levels of NFRs. Based on
simulations, we evidenced that our approach aims to explore reuse and is useful
for generating valid and optimal configurations. In addition, ToffA-DSPL
enables software engineers to conduct trade-off analysis, evaluate changes in
the context feature, and define an adaptation model from optimal configurations
found in the analysis.
