I find the thread a bit odd, although the topic interests me. Indeed, professionally I have quite a lot to do with safety cases and safety case requirements.
The subject is very broad, so here just a couple of pertinent comments.
First, Safety Cases are by no means the province of the oil and gas industry. Safety Cases are required by many national and international standards for various parts of safety-critical system lifecycles, under this or other names. For example, the international standard on functional safety for systems - any systes- which include electrics. electronics or programmable electronics, IEC 61508, requires a written document equivalent to a safety case. They are used extensively in UK MoD technical projects, and a recent set of observations on their use and misuse occurs in the report of Charles Haddon-Cave into the Nimrod accident and the history of the technical developments which led to it. That report illustrates quite clearly that safety cases are not a panacea, but that they can be misused just as any other tool. My colleagues at Adelard have a SW tool, ASCE, for safety case preparation, which is the result of nearly two decades of work and which is increasingly being used by UK MoD contractors. For a good introduction to the technicalities of safety case preparation, the
Adelard Safety Case Pages are amongst the very best available. (
GenghisE, that is,
John_T, I think (again), I hope you agree with me that this is an important reference, and not a commercial citation.)
The quick answer to "why don't airlines use safety cases?" is that the aviation industry has its own operational equivalents. In the case of an airline, it is the documentation required to obtain and maintain its AOC. ATC organisations increasingly use safety cases, labelled as such. Airplane manufacturers produce equivalent written documentation during certification.
So on one view, it is just not true that airlines don't use safety cases. They just don't call them that and it may be that the required arguments for safety in operations are spread over many documents rather than just one. Whether that is a good idea or not rather depends on how big the documentation is, and on whether the existing regime more or less works satisfactorily. Looking at the safety records of many of the world's better airlines, one would have to conclude that it does work pretty well.
All this is of course independent of what someone self-identifying as "Shell Management" might write on an anonymous public forum. My guess is that heshe is a poseur, but the issues raised, though provocatively, include good ones to which there are answers. More publicity about safety cases is in any case a good thing, and you know what they say - no publicity is bad publicity!
PBL