As academic learners and companies are turning to e-learning courses to achieve their personal and professional goals, it becomes more and more important to handle service quality in this sector. Despite scientific research conducted to personalize the learning process and meet learner's requirements under adaptive e-learning systems, however, the specification and management of quality attribute is particularly challenging due to problems arising from environmental variability. In our view, a detailed and high-level specification of requirements supported through the whole system lifecycle is needed for a comprehensive management of adaptive e-learning systems, especially in continuously changing environmental conditions. In this paper, we propose a runtime requirements monitoring to check the conformity of adaptive e-learning systems to their requirements and ensure that the activities offered by these learning environments can achieve the desired learning outcomes. As a result, when deviations (i.e., not satisfied requirements) occur, they are identified and then notified during system operation. With our approach, the requirements are supported during the whole system lifecycle. First, we specify system's requirements in the form of a dynamic software product line. This specification applies a novel requirements engineering language that combines goal-driven requirements with features and claims and avoid the enumeration of all desired adaptation strategies (i.e. when an adaptation should be applied) at the design time. Second, the specification is automatically transformed into a constraint satisfaction problem that reduces the requirements monitoring into a constraint program at runtime.