[SystemSafety] Correctness by Construction

[Olwen Morgan]

Agree entirely. I'd add only that there seems to be an insidious rotten 
culture in some parts of systems engineering that believes that dire 
weaknesses in physical or electronic design can be adequately 
compensated for by computation. ... Airframe aerodynamically unstable on 
takeoff? ... No problem - we'll fix it in the software!


I favour public hangings ... pour encourager les autres. ... :-O

Olwen


On 10/07/2020 10:59, Tom Ferrell wrote:
> Just echoing Paul's post.  The mainstream media insists on indicting the MCAS software.  Everything that has been made public to date points to software performing exactly as specified.  The problems were upstream with system definition and a flawed system safety process.  This was, indeed, compounded by numerous organizational failures driven by both conscious and unconscious biases and motives.
>
> -----Original Message-----
> From: systemsafety <systemsafety-bounces at lists.techfak.uni-bielefeld.de> On Behalf Of paul_e.bennett at topmail.co.uk
> Sent: Friday, July 10, 2020 5:48 AM
> To: systemsafety at lists.techfak.uni-bielefeld.de
> Subject: Re: [SystemSafety] Correctness by Construction
>
> On 7/10/2020 at 9:43 AM, "Michael Jackson" <jacksonma at acm.org> wrote:
>> CbyC is invaluable in avoiding errors in reasoning about formal models.
>> But the relationship of a formal model---whether of a computer or of
>> the real world of a cyber-physical system---may be a more prolific
>> source of faiure. Recent posts cited the 737Max8 disasters. Were these
>> due to formal errors in MCAS code?
> >From what I understood about the situation, was that it was a systematic error of the design and development process itself, and an imperative to keep high profits for the company putting pressure on the regulatory staff. The 737Max was, essentially, a new aircraft but was not evaluated as such.
>
> Regards
>
> Paul E. Bennett IEng MIET
> Systems Engineer
> Lunar Mission One Ambassador
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