The specific constraints that must be satisfied by embedded systems, such as timeliness, energy efficiency of battery-operated devices, dependable operation in safety-relevant scenarios, short time-tomarket and low cost, particularly in consumer products, coupled with the never-ending pressure to increase the functionality, lead to an enormous growth in the complexity of the design at the system level. In this paper we investigate the notion of design complexity, building on insights gained from research in the cognitive sciences. We argue that it is not the embedded system, but the models of the embedded system that must be simple and