Software product lines promise benefits like development and maintenance effort reduction, time to market decrease, and quality improvement, all resulting from planned and systematic reuse of common core assets. However, very little quantitative data has been measured so far to prove these promises. This paper formulates and discusses 7 hypotheses on how the promised advantages would look like in a quantitative way. It is meant to be a starting point for discussion on how to quantify which product line benefits and how they can be measured.
