Re: JOB:Sr. SW Engineers Wanted-Fortune 500 Co

[Scott Ingram <scott@silver.jhuapl.edu>]

Hyman Rosen wrote:
> 
> OK, I'm being a smartass, but I am making a valid point.
> Having its software written in Ada was not enough to keep
> the Ariane 5 from going off-course and being blown up. In
> the same way, having the software of a pacemaker written
> in C is not enough to force it to blow up. I would assume
> that pacemaker software undergoes thorough critical-systems
> development and testing regardless of what language it's
> written in.

I spent my high school years working in Emergency Rooms and 
Intensive care units with cardiac monitoring devices that I
later took a job as final test and calibration technician for.

Testing and cal were fairly well defined, and after I finished
with them they went to a QA inspector whose procedure differed
slightly from mine.  I used the lead set supplied with the device
from the production line, and the QA inspector used a set that
stayed at her bench.  It was only after a device had failed QA
4 consecutive times and I went to watch her do QA that I realized
where the problem lay.  The soldering process for the lead set
socket wasn't appropriate, and most, if not all of the monitoring
devices were defective.  Since this is a diagnostic tool used
when a patient is already in extremis, chances of applying a
harmful or deadly treatment were incredibly high.  Every device
of that model had to be called in for repair.

Admittedly, using Ada won't solve all bugs and can't fix poor
hardware design--but its usually one of the first tools I pull
out because its so good at helping me not make mistakes in the
first place.  And I know from frighteningly real experience
that testing can be flawed.
-- 
Scott Ingram
Sonar Processing and Analysis Laboratory
Johns Hopkins University Applied Physics Laboratory