In the domain of soft real-time application design, the gap between component-specification models and the implementations often implies that the implementations cannot fully take advantage of the specification models. To limit this gap, this paper proposes an approach to generate a QoS monitor from the timed behavior specification. To support this approach, we rely on two different component models: one focused on formal description and the other on practical implementation. Those models are interconnected by model transformation, using a Model-Driven Engineering style.