We show that timed automata can be used to model and to analyze timeliness properties of embedded system architectures. Using a case study inspired by industrial practice, we present in detail how a suitable timed automata model is composed. Exact upper bounds on the timeliness properties can be found with the Uppaal model checker for a number of usage scenarios. We compare our results with three other performance modeling techniques. This comparison shows that if the state space of the model is tractable, Uppaal gives the most accurate results at similar cost. The proposed modeling strategy can be automated, which alleviates the difficulty and error-proneness of manually constructing timed automata models.