The specification of requirements is a key activity for achieving the goals of any software project and it has long been established and recognized by researchers and practitioners. Within Software Product Lines (SPL), this activity is even more critical owing to the need to deal with common, variable, and product-specific requirements, not only for a single product but for the whole set of products. In this paper, we present a Feature-Driven Requirements Engineering approach (FeDRE) that provides support to the requirements specification of SPL. The approach realizes features into functional requirements by considering the variability captured in a feature model. It also provides detailed guidelines on how to associate chunks of features from a feature model and to consider them as the context for the Use Case specification. The evaluation of the approach is illustrated in a case study for developing an SPL of mobile applications for emergency notifications. This case study was applied within 14 subjects, 8 subjects from Universitat Politècnica de València and 6 subjects from Federal University of Bahia. Evaluations concerning the perceived ease of use, perceived usefulness, effectiveness and efficiency as regards requirements analysts using the approach are also presented. The results show that FeDRE was perceived as easy to learn and useful by the participants.