Re: Critique of Ariane 5 paper (finally!)

["Marin David Condic, 561.796.8997, M/S 731-96" <condicma@PWFL.COM>]

Robert Dewar <dewar@MERV.CS.NYU.EDU> writes:
>Note incidentally tha DBC seems to be a slippery character in this argument.
>At one end it is a very specific technique embodied in syntax in the tools
>being used, and at the other (see quoted paragraph above), it is referred
>to as though it is little more than the idea of saying what components of
>a program should do.
>
>Well of course if we take the second view, then it is certainly true that
>far more programs meet this criterion, which has by now been watered down
>to little more than "you should comment your programs properly".
>
>However, even with this watered down viewpoint, not all reliable programs
>meet the criterion. From time to time, there have been people holding the
>strong position that code should be self-documenting and that comments or
>documentation of any kind of the code is evil, becuse it could be wrong.
>
>I personally think this viewpoint is ludicrous and off the wall, BUT
>I would not for a moment claim that people following this viewpoint cannot
>produce reliable software (I know of counter examples -- yes, they surprise
>me, but the fact is that competent people can do almost anything with almost
>any tools, so general rules of good practice are almost never absolute).
>
    How about this: Build a random code generator which fills the
    first hundred or so words of memory with instructions. Execute
    those instructions. If the instructions output the string "Hello
    World!" once and then halt, the code has met the requirements and
    the image is to be saved for future executions.

    No DBC. No Object Oriented Design/Programming. No structured
    programming. No code walk-throughs. No methodology. No nothing. Yet
    I'd bet that a program could be constructed this way and be 100%,
    double-your-money-back-guaranteed reliable (Barring "Acts Of God"
    such as power outages! But then, that's a *hardware* reliability
    problem.:-) Software doesn't rot, rust or wear out, so the MTBF
    can be considered infinite.

    In other words: If you can think of only one way to solve a
    problem, then clearly you have not thought about it long enough. A
    jingoistic support of some method or technique as "the only"
    method or technique that can produce reliable, safe, "good"
    software is not particularly helpful. It also ends up insulting
    the folks who *do* produce reliable, safe, "good" software using
    other techniques as if they don't know their business.

    MDC

Marin David Condic, Senior Computer Engineer     ATT:        561.796.8997
Pratt & Whitney GESP, M/S 731-96, P.O.B. 109600  Fax:        561.796.4669
West Palm Beach, FL, 33410-9600                  Internet:   CONDICMA@PWFL.COM
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