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From the lens POSIWID - The Purpose of a System is what it Does.

  • puranroy Dec 22, 2010 @ 12:34 pm | delete
    This is little tough for me to understand. :(
  • William Livingston Mar 21, 2010 @ 1:50 pm | delete
    I heard Stafford give a speech in Orlando in 1986 where he used "The purpose of a system is what it does." Using the concept so much I found the phrase ungainly I came up with POSIWID as a code word. In 1993 when I went to see Stafford in Toronto, I presented him with a pen I had engraved with POSIWID. He sort of chuckled and that was the end of it.

    POSIWID is always used as an absolute. That is, no assignations about purpose are invented. What it does is, by definition, its purpose. I have never encountered a disconfirming example, nor have any of the thousands that have adopted the concept. Of course, it all started with Ashby.
  • Chris Bird Mar 30, 2009 @ 8:06 am | delete
    The "Purpose" in POSIWID is an unfortunate use of the term. Purpose implies a look forward a view into the future. However in POSIWID the idea is to look backwards. Just because someone uses a screwdriver to stir paint doesn't make paint stirring a purpose of a screwdriver. It does make it a use and it is interesting to explore why it is used that way, but that isn't a purpose.

    Some reasons why people might choose a screwdriver to stir the paint include:
    They didn't have anything else
    The screwdriver was going to be harmed less than the pen
    They were too lazy/inform to pick up the stirrer that was on the ground - the screwdriver was easier
    They wanted to annoy the screwdriver's owner
    Because the stirrer was dirty and the screwdriver clean

    When wanting to understand the reasons why it is very valuable to go from effect to cause (think root-cause analysis appraaches), and don't expect to find only one.

by

RichardVeryard

Writer: systems thinking for demanding change.

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