Both the scale and the reach of computer systems and embedded devices have been expanding constantly over the last few decades. As computer systems become pervasive, their criticality increases because they become an even more integral part of the infrastructure upon which our society depends. Hence, pervasive systems are likely to become "society critical" and their dependable operation must be ensured..

Since the number of computing nodes in a pervasive system will be much greater than in traditional dependable systems, the operating cost per node needs to become much lower. Therefore, more cost effective dependability mechanisms need to be deployed to achieve the desired degree of dependability at a given maximum operating cost..

In this paper, we explain the notion of pervasive dependability and outline some of the challenges we face in achieving pervasive dependability. We then describe our component based data-flow oriented middleware that we use as a test bed to investigate how to address these challenges.