On software quality and engineering

[Michael Bennett]

On Saturday 02 Nov 2002 5:12 pm, Steve Jenkin wrote:
> Simon Fowler wrote: [[Sat, 2 Nov 2002 10:42:35 +1100]]
>
> > I think the difference with software is that it's not like a
> > physical system - it doesn't wear out over time, it doesn't have an
> > inevitable failure at some point in the future, even if it's perfect
> > now. Software is either correct or it's not correct.
>
> Software _does_ wear out over time.  The term is 'bit rot'.
> This is what Y2K was about.

The software does not wear out. It was working exactly as programmed. It was 
either not designed/implemented correctly or was operating outside the design 
constraints (ie after 31 Dec 1999).

> Classes of bug/'defect' fixes:
> - corrective [fix faulty operation.  Doesnt meet a specification item]
> - perfective [adding a feature]
> - adaptive   [adapting to a changed environment.  Could be legistation, new
> O/S, ...]
>
> cheers
> sj

Michael Bennett.