Re: Writing better software was: Design by Contract (was Re: Interesting thread in comp.lang.eiffel)

[Stefan Skoglund <stetson@ebox.tninet.se>]

Ken Garlington wrote:
> Actually, that's typical for safety-critical software -- for example, I
> don't think we've ever received a single defect report from the field for
> the production F-16 or F-111 digital flight controls.

Those are military program with the belonging red-tape. Look up the
Therac-25
failures. In that case it was a purely commercial program with the
correspondingly
lack of red-tape ie that for example the FDA but also the users didn't
implement
some of the measures which is standard issue in military programs for
example
proper reporting of incidents.

In the Therac-25 case it was a classic example of a weakness transfering
in a error
and then into system failure.

Hmm wondering why the Therac-25 debacle wasn't in my real-time
programming tution.

> both "management science" and "computer science" (not that those are
> entirely disjoint terms).

ie what you do before you start project definition and after system
employement.

> 
> However, they will also tell you that their dollars invested per SLOC is
> much higher than the industry average (again, typical for safety-critical
> software). It may be that using more "computer science" (e.g., using more
> COTS) will permit lower costs while still retaining the kinds of defect
> rates expected for this type of software.

I doubt it considering that it will only cut down on amount on coding.
You still
must do proper testing for example.