  When considering the accuracy of sensors in an automated vehicle (AV), it is
not sufficient to evaluate the performance of any given sensor in isolation.
Rather, the performance of any individual sensor must be considered in the
context of the overall system design. Techniques like redundancy and different
sensing modalities can reduce the chances of a sensing failure. Additionally,
the use of safety models is essential to understanding whether any particular
sensing failure is relevant. Only when the entire system design is taken into
account can one properly understand the meaning of safety-relevant sensing
failures in an AV. In this paper, we will consider what should actually
constitute a sensing failure, how safety models play an important role in
mitigating potential failures, how a system-level approach to safety will
deliver a safe and scalable AV, and what an acceptable sensing failure rate
should be considering the full picture of an AV's architecture.
