  Progress in the behavioral analysis of software product lines at the family
level benefits from further development of the underlying semantical theory.
Here, we propose a behavioral equivalence for feature transition systems (FTS)
generalizing branching bisimulation for labeled transition systems (LTS). We
prove that branching feature bisimulation for an FTS of a family of products
coincides with branching bisimulation for the LTS projection of each the
individual products. For a restricted notion of coherent branching feature
bisimulation we furthermore present a minimization algorithm and show its
correctness. Although the minimization problem for coherent branching feature
bisimulation is shown to be intractable, application of the algorithm in the
setting of a small case study results in a significant speed-up of model
checking of behavioral properties.
