SafetyCase

Safety is a property of a system that is difficult to verify quantitatively since no clear measurement method exists that can be applied during the development. Not even exhaustive testing is feasible, as faults in electronics can have an intensity of 10^-9 faults/hour and still pose an unacceptable risk. Hence, it is only when sufficient field data have been collected from a system used in a particular context that it can be said to be safe enough. Nonetheless, safety must be addressed and assessed during development, restricted to qualitative reasoning about the safety of a product. A structured engineering method is thus needed to approach this problem. One such method is the so called safety case, which came originally from the nuclear industry.<br/>