From: dewar@cs.nyu.edu (Robert Dewar)
Subject: Re: Need help with PowerPC/Ada and realtime tasking
Date: 1996/05/27
Date: 1996-05-27T00:00:00+00:00 [thread overview]
Message-ID: <dewar.833197805@schonberg> (raw)
In-Reply-To: 355912560wnr@diphi.demon.co.uk
JP Thornley said
"My view is that code can never be judged as safe or unsafe - only
correct or incorrect. However my usage of the words "safe" - and
"safety-critical" carries a lot of additional baggage, and it is
possible that we are differing over the meaning of these words rather
than anything fundamental.
"
I think that is completely wrong. Correctness, i.e. formal conformance
between the implementation and the specification, is neither necessary
nor sufficient for safety.
It is not necessary, because there can be deviations that are not
life-critical, e.g. if the horizon display on the pilots console
is not the specified shade of green, it is not critical.
It is not sufficient, because the formal specification may be incomplete
or incorrect.
next prev parent reply other threads:[~1996-05-27 0:00 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
1996-05-17 0:00 Need help with PowerPC/Ada and realtime tasking Dave Struble
1996-05-18 0:00 ` JP Thornley
1996-05-20 0:00 ` Robert I. Eachus
1996-05-21 0:00 ` Michael Levasseur
1996-05-21 0:00 ` Richard Riehle
1996-05-25 0:00 ` JP Thornley
1996-05-27 0:00 ` Robert Dewar [this message]
1996-05-28 0:00 ` JP Thornley
1996-05-29 0:00 ` Ken Garlington
1996-05-29 0:00 ` Robert A Duff
1996-05-30 0:00 ` Software Safety (was: Need help with PowerPC/Ada and realtime tasking) Ken Garlington
1996-05-30 0:00 ` Robert Dewar
1996-06-02 0:00 ` JP Thornley
1996-06-03 0:00 ` Robert A Duff
1996-06-05 0:00 ` Norman H. Cohen
1996-06-07 0:00 ` Ken Garlington
1996-06-12 0:00 ` Norman H. Cohen
1996-06-12 0:00 ` Ken Garlington
1996-06-08 0:00 ` Robert Dewar
1996-06-08 0:00 ` Robert A Duff
1996-05-31 0:00 ` Robert A Duff
1996-06-03 0:00 ` Ken Garlington
1996-05-30 0:00 ` Need help with PowerPC/Ada and realtime tasking JP Thornley
1996-05-31 0:00 ` Ken Garlington
1996-06-02 0:00 ` JP Thornley
1996-06-03 0:00 ` Ken Garlington
1996-05-25 0:00 ` JP Thornley
1996-05-27 0:00 ` Darren C Davenport
1996-05-30 0:00 ` Ralph E. Crafts
1996-05-31 0:00 ` JP Thornley
1996-06-03 0:00 ` Ken Garlington
1996-05-28 0:00 ` Tasking in safety-critical software (!) (was Re: Need help with PowerPC/Ada and realtime tasking) Kevin F. Quinn
1996-05-28 0:00 ` Need help with PowerPC/Ada and realtime tasking Robert I. Eachus
1996-05-30 0:00 ` JP Thornley
1996-05-28 0:00 ` Robert I. Eachus
1996-05-30 0:00 ` JP Thornley
1996-06-03 0:00 ` Ken Garlington
1996-05-31 0:00 ` Robert I. Eachus
1996-06-03 0:00 ` Ralph Paul
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