Typically, the detection add-ons may not be activated in normal operation. They should operate only they are needed. Therefore, by default, the secondary risks may not be detected in time. Special means should be designed to ensure timely detectability.
The detection add-ons should be reliable, and special procedures should be employed routinely, to enable timely detection of failure of the detection add-ons.
The signals used in normal sensors operation should be different from the signal received in case of failure. Special rules should be formalized and implemented to enable detection of the faulty situations.
Special rules should be formalized and implemented to enable detection of unexpected behavior of the gates and the situation analyzers.
The operators should be reported about all situations of detection failure.
The information should not be intrusive. It should be visible and salient, but it should not interfere with the other operational activities.
Updated on 15 Oct 2016.