Hazards error signals

Human operators who control and supervise the production process in hazardous plants make decisions based on the signals and indications presented on interfaces that should be carefully designed especially for potential abnormal situations and critical events. The research findings concerning the industrial accidents indicate that 70-90% of accidents were caused due to human errors and related failures influenced... 

The transmitter failure rate (2-xxi) is the sum of all the components failure mtes (Equation 1) which are involved in the generation of the energizing signal, and its amplification. As the BIST topology is not included, every time the BTM has an error, the safety requirement is not accomphshed. So the hazard rate is the same as the failure rate. 

One of the first steps recommended in lEC 61508 is to determine the boundary of the Equipment Under Control (EUC) and the EUC control system. Since lEC 61508 is directed towards programmable electronics systems, it is natural to think of the road and its users as the EUC and the ITS as the control system. Under such a model, it is also natural to consider modelling hazards at the boundary of the control system, e.g. at the level of errors in the display of signs and signals. 

---