Reducing combinatorics in testing product lines

A Software Product Line (SPL) is a family of programs where each program is defined by a unique combination of features. Testing or checking properties of an SPL is hard as it may require the examination of a combinatorial number of programs. In reality, however, features are often irrelevant for a given test - they augment, but do not change, existing behavior, making many feature combinations unnecessary as far as testing is concerned. In this paper we show how to reduce the amount of effort in testing an SPL. We represent an SPL in a form where conventional static program analysis techniques can be applied to find irrelevant features for a test. We use this information to reduce the combinatorial number of SPL programs to examine.