On software quality and engineering

[Tomasz Ciolek]

Brad,

> A concept that has been missed in all of this is that all things are designed 
> to meet acceptable risk. The Pinto example is where they mis-defined what 
> level of risk was acceptable.
[SNIP LOTS]

I think that you raised an important point, with regard to engineering
as a whole. I agree that complex system will fail. Howevere there
appears to be a very major difference in the culture of engineering
material objects and software.

That difference appears to be this:

When in the physical world, a particular wiget A is designed, it carries with it a set of specifications that say "it was designed to operate in such and such conditions under such and such a minimum and maximum loads, etc... " and has some safety margins built in. In most cases of software desing I am yet to see doco on a module that states that: "this module implements function X, it has these input ranges, these output ranges and produces this error otherwise".

regards
Tomasz Ciolek

-- 
Tomasz M. Ciolek	*
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