Method for determining residue failure rate of signal chain

The invention provides a method for determining residue failure rate of a signal chain in car safety completeness grade evaluation. The flow path of signals in signal chain evaluation includes: acquiring corresponding PPM values for elements which can not acquire failure modes and corresponding failure rate, wherein the PPM values refer to the bad element amount in the designated amount during a designated period; utilizing the acquired PPM values of the elements of different working section in all failure modes related to the safety according to the above elements and utilizing the weight between failure rate and working section related to the safety to calculate data to perform weighted mean on the acquired judgment identification rate so as to further acquire judgment non-identification rate of the element; acquiring residue failure rate of the element related to the safety based on the metering failure rate of the element and the judgment non-identification rate; acquiring residue failure rate related to