Rick Marshall wrote:
> 2) software systems do degrade, as mentioned by
> changing external systems. but with modern hardware reliability i think
> hardware now has more in common that software in this respect. eg most
> of the hardware upgrades we complete are now due to obsolesence rather
> than failure
In computers, perhaps. But in airplanes, automobiles, lawnmowers,
microwave ovens, refrigerators, and many other forms of hardware, no.
The fact is a modern computer doesn't have all that many moving parts,
which is what leads to parts wearing out. (There's the hard drive, the
fan, the CD-tray, maybe a button or two, anything else?) However, even
well-lubricated, well-maintained motor based hardware experiences
significant friction that will degrade parts over time. Off the top of
my head I don't know why microwave ovens wear out, but they certainly do
as well. There's just no equivalent to friction-driven wear-and-tear on
software.
--
Elliotte Rusty Harold
XML in a Nutshell 3rd Edition Just Published!
http://www.cafeconleche.org/books/xian3/
http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim
