  Software Product Lines (SPL) are inherently difficult to test due to the
combinatorial explosion of the number of products to consider. To reduce the
number of products to test, sampling techniques such as combinatorial
interaction testing have been proposed. They usually start from a feature model
and apply a coverage criterion (e.g. pairwise feature interaction or
dissimilarity) to generate tractable, fault-finding, lists of configurations to
be tested. Prioritization can also be used to sort/generate such lists,
optimizing coverage criteria or weights assigned to features. However, current
sampling/prioritization techniques barely take product behavior into account.
We explore how ideas of statistical testing, based on a usage model (a Markov
chain), can be used to extract configurations of interest according to the
likelihood of their executions. These executions are gathered in featured
transition systems, compact representation of SPL behavior. We discuss possible
scenarios and give a prioritization procedure illustrated on an example.
