Safety case study

The safety case process has ceased to be seen as the cause of extensive delays to the introduction into traffic of perfectly "safe" new rolling stock. The provision of a safety case has not prevented recent tragic accidents, but these accidents were not caused by a failure of the rolling stock safety case. It could be argued that they were primarily caused by a failure to apply the same rigorous safety case regime to operations and maintenance as is applied to newly built trains. This paper is an attempt to show how the safety case process used by Siemens has developed in the last few years, together with some observations on problems and possible solutions