New subject: repair on site

7 Oct 2001

ard(a)p850ug1.demon.co.uk wrote:
...
  If I was being totally honest, I would probably admit
that there are 
 times where board-swapping makes sense. Not _all the time_, though... 
 There are certainly times when component level repair make financial 
 sense (even when you consider the time taken to replace the 
 component), 
 and is also the fastest way to get the machine working again. 
I cannot think of too many cases (at least in our
current machine room - or indeed anywhere else
I have been) where a repair is better for either the
customer or the repairer. If I look at the routers and
switches in our racks, the PSUs swap out, the fan tray
swaps out and all of the cards swap out. The backplane
and switching fabrics are a little harder - but not much.
Replacing a card is the work of moments and will be much
cheaper for the customer (in terms of down time) and
the supplier (in terms of the amount of training
needed by the FE).

Even five to ten years ago (the times of the VAX 4000
and VAX 6000) I expect that the same economics would
have applied. In fact, I believe that the machines
were designed to keep MTTR low (and MTBF high !).

You would have to go back to the early eighties,
the days of the VAX-11/7xx and the VAX 86xx, to 
find FEs fixing components on site. In those days
machines cost a great deal more and people (even
highly trained people) cost a great deal less.

Now once the card has been pulled and returned to
base, then it is probably worthwhile having a repair
line where someone with the appropriate skills
can find the fault and fix it. Obviously if it costs
more to do this than it does to simply use brand new
boards as swap-ins, then even this repair won't be
done.

This is not to say that I won't fix the washing machine
or the TV myself once they go out of waranty (but
even there it was cheaper to get a new drain pump
than try to repair the broken one!)

...
  No, what worries me is that people are not being
taught about
 component-level design and repair any more (design and repair 
 are not the same thing, of course). 
I too am concerned about that sort of dumbing down.
At least in those courses where it is appropriate.
OTOH it seems perfectly reasonable to me that *most*
people could care less about how their computer
works - after all most people seem to be that way
about their TV, car, DVD etc. I, for one, do
not particularly enjoy plumbing, for example.

...
   replacement
modules. People like Tony are few and far between.  
 Probably because very few employers want people like me.... 
Economics again. Employers only need one of you
for every N field service engineers. Your kind
of skills cost money ... and if they don't you
aren't doing the rest of us any favours - stop it :-)

Antonio

IBM ROM BASIC or lack thereof