[SystemSafety] Modelling and coding guidelines: "Unambiguous Graphical Representation"

[David MENTRE]

Hello,

Le 04/03/2016 01:38, Steve Tockey a écrit :
> Of course code has a finite lifetime. But I think it's worth asking, "what
> drives that lifetime to be what it is?" I see two drivers. One is product
> (functional) obsolescence, the world moves on and other, presumably more
> capable, software becomes available. Why use the old, limited version when
> a new all-the-bells-and-whistles product is available?
>
> The other is deterioration. Unlike hardware things that wear out because
> of use, software tends to deteriorate because downstream maintainers
> violate initial design principles, etc. It's the on-going accumulation of
> so-called technical debt. If the software starts off with a huge amount of
> technical debt from version #1, it only gets worse from there. On the
> other hand, if version #1 is very clean and downstream maintainers work to
> keep it that way, code lifetimes can be quite long.

In fact, David L. Parnas expressed the very same idea in 1994: ;-)
   "Software Aging"
 
http://www.inf.ed.ac.uk/teaching/courses/seoc/2004_2005/resources/bullet11.pdf

Best regards,
david