One of the features that will be demonstrated in this case study is automatic ASIL allocation and decomposition. It is then necessary to assign each hazard with an ASIL.  H1, loss of braking, is assigned ASIL D and H2, wrong value braking, is assigned ASIL A. This was done solely on the basis of the severity of each hazard, as this is an illustrative example. For a 'real situation' ISO 26262 risk assessment procedure would be undertaken.

For cost optimisation during ASIL assignement, the user is allowed to define an heuristic that expresses the cost of a component in function of its ASIL implementation. For this case study it was used that agrees with what seems the industry perspective, and that expresses that the highest cost jump is between ASIL B and ASIL C.


Table 5 - ASIL Cost Heuristic
Cost  0 10  20  40 50