Quote:
"However the chance of software produced by two independent teams who have submitted two *completely* different implementations coming up with the same erroneous value has to be considered pretty damn remote."
My experience of software development is limited to non safety-critical applications (test and implementation of custom software in print media.) I am not, and have never been, in the aviation industry and I also lack formal training in computer science, so I'm excessively unqualified to make any kind of comment here... However I've heard it said that the above assumption is significantly undermined by a "common culture" shared by programmers.
Whether this gotcha is now compensated for by appropriate strategies, I have no idea, but it does seem to me a real hostage to fortune to assume that any area of human endeavour has reached the stage of unblemished perfection - least of all software!