Safety Element is a HW, SW or System Element that is Safety relevant. When we say “Safety relevant”, it means that it is in some way contributing to achieving or violating the Safety goal. Let’s assume a Safety goal for an Instrument Cluster system, “The Airbag telltale must be indicated on the TFT during Ignition ON when activated”. A diagrammatic representation of this system is given below. There are two Controllers in the System, a Vehicle processor and a Graphics processor. The telltale is turned ON based on CAN signals received from the Airbag ECU. The Inputs for this Safety goal is the CAN input and Ignition, and the output is the bitmap indicated on the TFT display. The picture shows the path of the telltale in the System, from input until output. As it can be noticed, there are several HW and SW components that participate in this path. These are all in some way contributing towards indicating the Airbag telltale on the TFT. Or, if they weren’t functioning properly, it ...
