[time-nuts] Simulation

Magnus Danielson magnus at rubidium.dyndns.org
Sat Aug 14 15:50:50 UTC 2010


On 08/14/2010 05:08 PM, J. Forster wrote:
> FWIW, IMO any engineer who uses undocumented or uncontrolled parameters or
> instructions in a production design is a fool.
>
> If you are that silly, you must fully specify the selection criteria.

Using non-spec aspects needs documentation, motivation and risc analysis.

I've designed a selection routine for a component which still ticks on 
with good statistics. The main problem is that eventually that component 
will be on last buy level. Obviously it seems the selection was chosen 
on the conservative side, so it works in shipped products regardless of 
batch. Trimming of the manual routine has lowered a certain failure mode 
of testing.

Any spec should be verified. Published specs needs verification with 
real components. Unpublished specs needs consistency testing or even 
selection testing on all components. Cost of testing needs to be 
understood and risc of low yield in future needs to be understood and 
alternative approaches could be put in place before running on flat tires.

At times it may be cheaper and safer to run with more expensive 
components which is within spec.

Cheers,
Magnus



More information about the time-nuts mailing list