  Variational systems allow effective building of many custom variants by using
features (configuration options) to mark the variable functionality. In many of
the applications, their quality assurance and formal verification are of
paramount importance. Family-based model checking allows simultaneous
verification of all variants of a variational system in a single run by
exploiting the commonalities between the variants. Yet, its computational cost
still greatly depends on the number of variants (often huge).
  In this work, we show how to achieve efficient family-based model checking of
CTL* temporal properties using variability abstractions and off-the-shelf
(single-system) tools. We use variability abstractions for deriving abstract
family-based model checking, where the variability model of a variational
system is replaced with an abstract (smaller) version of it, called modal
featured transition system, which preserves the satisfaction of both universal
and existential temporal properties, as expressible in CTL*. Modal featured
transition systems contain two kinds of transitions, termed may and must
transitions, which are defined by the conservative (over-approximating)
abstractions and their dual (under-approximating) abstractions, respectively.
The variability abstractions can be combined with different partitionings of
the set of variants to infer suitable divide-and-conquer verification plans for
the variational system. We illustrate the practicality of this approach for
several variational systems.
