[SystemSafety] Overflow triggering AC power cut-off in Boeing 787

[jean-louis Boulanger]

The question raised by david is related to "do you have some additional
informations on this issue" ?

before discussing of tools, we need to discuss of methodology, in this
case, do you have a systematic activity to detect overflow ?
if yes when an overflow is identified, it's remove or can we accept it
after justification ?

for tools, actually, we have very powerful formal tools that check many
thing and we demonstrate (in many industrials used) that its work.
yes we can have false positive but manually manage X00 000 lines of code is
not easy ....
yes we can have some lack (partial coverage of language, efficiency, ...)
but a tools is an help

actually, the different standards requested some tools qualification effort
and evidence ....

...

2015-05-03 19:48 GMT+02:00 Derek M Jones <derek at knosof.co.uk>:

> David,
>
>  This would not happen if absence of overflow was automatically checked
>> (by using tools like Frama-C, Astrée or Polyspace). Or more probably
>>
>
> Automatic checking is not in itself enough and without the source code
> to try out the tools you cannot claim that any of them
> would have detected the problem.
>
> Deciding what kinds of thing a static analysis tool involves
> lots of trade-offs, such as:
>
>    o what can be implemented with the available resources,
>
>    o what level of false positive is considered acceptable,
>
>    o what kinds of mistakes are most likely to occur and hence
>      the ones for which it is cost effective to check for,
>
>    o for commercial tools, what the customer wants to know and what they
>      are willing to pay,
>
>    o for academic projects, what is likely get published when written
>      up.
>
> --
> Derek M. Jones           Software analysis
> tel: +44 (0)1252 520667  blog:shape-of-code.coding-guidelines.com
>
> _______________________________________________
> The System Safety Mailing List
> systemsafety at TechFak.Uni-Bielefeld.DE
>



-- 
Mr Jean-louis Boulanger
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