Te???a S?st?

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Te???a S?st?µ?t??

• ?a??a ?a??da
• mka_at_aegean.gr
• ??????S????? ??G????
• ????? ???????O? ?????F?????O? ??? ???????O????O?
  S?S?????O?
• G ?????

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?e??e??µe??

• ??µ?µ??a ?a? ad?µ?ta p??ß??µata
• SSM
• Systems Dynamics
• Te???a ?????

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??µ?µ??a ?d?µ?ta p??ß??µata

• ?? ???e? ??a p??ß??µa d?s????
• ??µ?µ??a p??ß??µata
• Safe?? pe?????sµ??, pe?????sµ???? ????? ??se??,
  ?p???e? ??s?, ?µfas? st? p??
• p.?. a?t?µet?p?s? ?a???a???a?
• ?? d?µ?µ??a p??ß??µata (?µ?d?µ?µ??a ?d?µ?ta)
• ???a? s?µp???a, de? eµfa?????ta? µe t?? ?d?a
  µ??f? ???e f???, de? a?t?µet?p????ta? µe
  s?st?µat??? t??p? (apa?t??? ad hoc ??se??).
  S??d?asµ?? e??t?se?? t? ?a? p??
• p.?. ? a?aß??µ?s? t?? pa?de?a?

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?a?a?t???st??? d?µ?µ???? p??ß??µ?t??

• ?? s????? t?? e?a??a?t???? t??p?? d??s?? e??a?
  pepe?asµ???, a???µ?s?µ? ?a? f?a?µ???.
• ?? ??se?? p????pt??? µe ?????? s???pe?a ap? ??a
  eµpe????? µ??t???, t? ?p??? pa???s???e? ?a??
  a?t?st????a µe t? p??ß??µa, ?p?? ???eta?
  a?t???pt?.
• ? ap?te?esµat???t?ta ?a? ? ap?d?t???t?ta t??
  d?af???? t??p?? d??s?? µp??e? ?a e?t?µ??e?
  a???µ?t??? (p?s?t???p???s?) ? t??????st?? µe
  a?t??e?µe???? t??p?.

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?a?ade??µata

• ???pt??? epe?e??ast? 4GHz
• ???pt??? ?????f???a??? S?st?µat?? ??a t?
  G?aµµate?a t?? ???S
• ??t?µet?p?s? pa?ap???? t?? e?????? p??????f??
  ?t????? ??a t?? a?aµ??? ???s?? t?? a?e???st????.

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???ß??µa a?aµ???? a?e???st????

• O? d?µ?µ??? p??ß??µa
• ??as??? p??ß??µa ????? a?aµ????, ??a ????
  a?t?µat?? µ??a??sµ??.
• ?e???sµ?? ap? ???????? 4 x 2000 x 14, a?? ?t??.
• ??µpt??, e??te?????, a?e???st??a?, 50000
• S???et?? p????aµµat???µe??? µ??a??sµ??, 7000
• O? ad?µ?t? p??ß??µa

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?a?a?t???st??? ad?µ?t?? p??ß??µ?t??

• ?e? ?p???e? saf?? d?at?p?s? t?? p??ß??µat?? - ?
  d?at?p?s? e??a? µ???? t?? p??ß??µat??.
• Sta ad?µ?ta p??ß??µata, ?ta? p??spa?e?? ?a d?se??
  ??s?, de? ???e?? p?te ?a staµat?se??. ?e? µp??e??
  ?a pe?? ?t? ? ß??t?st? ??s? d????e ? ?a
  ap?de??e?? ?t? de? ?p???e? ??s?.
• ?e? ?p???e? s?st? ? ????? ??s?, a??? ?a?? ? ?a??
  ??s?.
• ?e? ?p???e? ?µes?? ?a? p????? ??e???? t??
  ap?te?esµat???t?ta? t?? ??s??.

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?a?a?t???st??? ad?µ?t?? p??ß??µ?t?? (s????e?a)

• ?e? ?p???e? t??p?? ?a ap?de????µe ?t? ?????
  e?etas?e? ??e? ?? p??a??? ??se??.
• ???e ad?µ?t? p??ß??µa e??a? µ??ad??? ?a? ??e? t?
  d??? t?? ad hoc ??s?. ? te????? d???µ? ?????
  (trial and error) de? ß????e?.
• ?? p??ß??µa µp??e? ?a e?µ??e?te? µe d??f?????
  t??p??? a?????a µe t?? ?pt??? ????a e??tas?? t??,
  ta p??t?pa ?a? t?? ???µe? p?? ?a ???s?µ?p???????.
  ? t??p?? e?µ??e?a? ?a?????e? ?a? t? e???? t??
  ??se??

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?a??de??µa ad?µ?t?? p??ß??µat??

• ?e?t??s? t?? ?p??es??? t?? G?aµµate?a? t?? ???S
• ?? ?a ße?t??s??µe
• ???
• ???a p??pe? ?a e??a? ? ta?t?t?ta t?? s????????
  ?a?ep?st?µ???

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Hard vs. Soft p??ß??µata

• ?a ?a?? d?µ?µ??a p??ß??µata ap??a????ta? ??aµpta
  (hard) e?? ta ad?µ?ta p??ß??µata ?a????ta?
  e?µet?ß??ta (soft) p??ß??µata.

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Hard vs. Soft p??ß??µata

• H. Simon t? d?s????te?? µ???? t?? ??s?? e???
  p??ß??µat?? e??a? ?a ?????µe t? s?st? e??t?s?.
• R. Ackoff e??a? p??t?µ?te?? ?a ????µe t? ?????
  ap??t?s? st? s?st? e??t?µa, pa?? t? s?st?
  ap??t?s? st? ????? e??t?µa.

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Hard vs. Soft p??ß??µata

• ??? µp????µe ?a d?at?p?s??µe ??a p??ß??µa, t?te
  µp????µe ?a ß???µe ?a? ??s? se a?t?. ?s??e?

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Hard vs. soft Systems

• ??? ??a s?st?µa ap?te?e? µ??t??? µ?a? d?µ?µ????
  ?at?stas??, ap??a?e?ta? hard system
• ?a s?st?µata p?? pe?????f??? t?? a?t????? µ?a?
  ad?µ?t?? ?at?stas?? ?a?a?t??????ta? soft
  systems.

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???s? µ??t????

• ??a µ??t??? ap?te?e? t?? pe????af?, ep?µ???? ?a?
  t?? ?ata???s?, µ?a? ?at?stas??.
• G?a ?a µp??e? ?a ???s?µ?p????e? p??pe? ?a
  ap?te?e? ap??p???s? t?? ?at?stas??.
• ? ß??t?st? ??s? e??? µ??t???? de? ap?te?e?
  apa?a?t?ta t? ß??t?st? ??s? t?? p??ß??µat??.

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Hard vs. Soft Systems Thinking

• ??????a µe t? p?? a?t??aµßa??µaste t? f?s? e???
  p??ß??µat?? µp??e? ?a ????µe d?? d?af??et?????
  t??p??? s?????
• Hard Systems Thinking ? st???? p?? p??pe? ?a
  ep?te???e? e??a? ded?µ???? ?a? µp????µe ?a
  a?apt????µe ??a s?st?µa p?? ?a ep?t?????e? t???
  st????? p?? ?????µe.
• Soft Systems Thinking ? st???? de? µp??e? ?a
  ?e????e? ded?µ????.

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Paradigms

• ? Checkland ?p?st????e? ?t? ?? d?? p??????µe?e?
  p??se???se?? ?d????? se d?? pa?ade??µata
  (paradigms).
• Paradigm I ? ??sµ?? ?e??e?ta? s?st?µ???? (d??.
  pe???aµß??e? s?st?µata), ? t??p?? p?? t??
  µe?et?µe e??a? s?st?µat???? (hard systems
  thinking).
• Paradigm II ? ??sµ?? ?e??e?ta? p??ß??µat????
  (problematic) ?a? t?? µe?et?µe s?st?µ??? (soft
  systems thinking).
• ???s?µ?p??e? t?? ??? p??ß??µat??? ?at?stas?, a?t?
  t?? ???? p??ß??µa.

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?a????µ?s? ?at? Checkland

• F?s??? s?st?µata
• ?p?????? st? s?µpa?
• S?st?µata a????p???? d?ast????t?ta?
• S????a d?ast????t?t?? t?? ?p??e? e?te????
  ?????p??, s???? se s??d?asµ? µe s?ed?asµ??a
  te????????? s?st?µata
• S?ed?asµ??a te????????? s?st?µata
• ?atas?e?????ta? ap? t?? ?????p?
• S?ed?asµ??a af???µ??a s?st?µata
• ???a s?st?µata p?? ?atas?e?????ta? ap? t??
  ?????p?.

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S?st?µata ?????p???? d?ast????t?ta?(Human
Activity Systems)

• ???a? ta s?st?µata sta ?p??a ?? d?ast????t?te?
  e?te????ta? ap? t??? a????p???, ??a ??p??? s??p?.
  ? ?µfas? sta s?st?µata a?t? e??a? st??
  d?ast????t?te? ?a? ??? sta ?t?µa.
• S.?.?. S?st?µa ??ast????t?t?? ?????????
  S?st?µa

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?a?a?t???st??? S.?.?.

• ??? ? ??a µ???? t?? s?st?µat?? ap?te?e?ta? ap?
  a????p??? (p.?. ?????f???a?? S?st?µa).
• ?? ?????p?? ????? d?af??et????? st????? ?a? a??µa
  ?ta? s?µf????? se ??a? ????? st??? ?????
  d?af??et??? a?t????? ??a t? p???? e??a? ?a? p??
  µp??e? ?a ep?te???e?.
• ?a S?st?µata ?????p???? ??ast????t?ta? s????
  a??????? s??p?.
• ?e? µp??e?? ?a ta pa?at???se??/µe?et?se??, ?????
  ?a ep??e?se?? t? s?µpe??f??? t???.

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???sµ?? S.?.?.

• ??a ???t??? s?st?µa µe st???, p?? e?f???e? µ?a
  a????p??? d?ast????t?ta t?? p?a?µat???? ??sµ??.
  ?a s?st?µata a?t? e??a? ???t??? µe t?? ?????a ?t?
  de? ap?te???? a???ß? pe????af? t?? d?ast????t?t??
  t?? p?a?µat???? ??sµ?? (p?? e??a? ?pe?ß?????
  pe??p???e?) a??? e??a? d?a???t???? ?atas?e???.
  ?p?te???? ?deat??? t?p??? ?a? ???s?µ?p?????ta?
  st? s???t?s? ??a t?? p??a??? a??a??? p?? µp??e?
  ?a e?sa????? se µ?a p??ß??µat??? ?at?stas? t??
  p?a?µat???? ??sµ??.
• "A notional purposive system which expresses some
  purposeful human activity, activity which could
  in principle be found in real world. Such systems
  are notional in the sense that they are not
  descriptions of actual real-world activity (which
  is an exceptionally complex phenomenon) but are
  intellectual constructs they are ideal types for
  use in a debate about possible changes which
  might be introduced into a real-world problem
  situation.
• P. Checkland

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S.?.?. ?a? Soft Systems Thinking

• Sta S?st?µata ?????p???? ??ast????t?ta? ta
  pe??ss?te?a p??ß??µata µp????µe ?a ta d??µe ??
  ad?µ?ta (soft problems).
• Sta S.?.?. a?t?µet?p????µe p??ß??µat????
  ?atast?se?? ?a? ??? ?a???-???sµ??a p??ß??µata.
  ??a st???? µa? e??a? ? ße?t??s? t?? p??ß??µat????
  ?at?stas?? ?a? ??? ? e?e??es? t?? ß??t?st??
  ??s??.
• ? Checkland ta ???µ??e? ?a? e?µet?ß??ta s?st?µata
  (soft systems) ?a? pa???e? µ?a µe??d?????a t??
  ?e??d?????a t?? ??µet?ß??t?? S?st?µ?t?? (Soft
  Systems Methodology - SSM).
• G?a t?? Checkland ta s?st?µata de? ?p?????? st??
  p?a?µat???t?ta, a??? e??a? ???t???? ?atas?e???.

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?e??d?????e? ??a t? µe??t? t?? e?µet?ß??t??
s?st?µ?t??

• ?µfas? st?? d?af??et???? ?pt???? a?t????e?? t??
  pa?at???t?? d?af??et???? ap??e?? e??a? ap?de?t??
• St???? e??a? ? ep?te??? s??-a?t?????? ?a?
  s??a??es?? ap? ????? t??? eµp?e??µe????
• ?e? ?p???e? a?t??e?µe????t?ta a??e?t?a t??
  e?d????.
• ? s??a??es? ep?t?????eta? µ?sa ap? µ?a d?ad??as?a
  µ???s?? ?a? a?????ep?d?as?? t?? eµp?e??µ????.

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• ?e??d?????a ??µet?ß??t?? S?st?µ?t?? (P. Checkland)

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?e??d?????a ??µet?ß??t?? S?st?µ?t??

• ??µata t?? ?e??d?????a?
• ??t????? t?? ad?µ?t?? p??ß??µat???? ?at?stas??.
• ?ept?µe?e?a?? ??f?as? t?? p??ß??µat???? ?at?stas?
  (?atas?e?? p???s?a? e????a?).
• ?µfas? st?? ?p?????sa d?µ?, st??? ??????
  (?d???t?t?? p??ß??µat??, ??pt?? ap?f?se??, ??t??
  p??ß??µat??), st?? ????t???a (???µe?, a??e?),
  s??se?? e???s?a?.
• ???f?p???s? ?a? pe????af? s?et???? s?st?µ?t??
  (ßas???? ???sµ?? s?st?µat??).
• ??µ??????a ?deat?? µ??t???? ap? ???e ßas???
  ???sµ?.
• S?????s? ?deat?? µ??t???? µe t?? p?a?µat???t?ta
• ?a????sµ?? ?a? s???t?s? p??? st?? ep???µ?t?? ?a?
  s??p?µe? a??a???
• ???sp??e?a ??a ße?t??s? t?? p??ß??µat????
  ?at?stas?? (???p???s?? a??a???)

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?a??de??µa p???s?a? e????a?
Source A. Monk and S. Howard, Methods tools
the rich picture a tool for reasoning about work
context, interactions, 5 (2), 1998
26
?a??de??µa ?atas?e??? p???s?a? e????a?

• ?e?????µe ???a s?st?µat??, eµp?e??µe????,
  pe??ß?????, s??se?? ?a? s??????se??
• ?ata???f??µe ßas????? p??ß??µat?sµ??? ?a? s???e??
  t?? eµp?e??µe???, ??t?µata d?µ??, pe?????sµ???.
• ? p???s?a e????a a?apt?sseta? epa?a??pt??? µe t?
  s??e??as?a ???? t?? eµp?e??µ????.

Source A. Monk and S. Howard, Methods tools
the rich picture a tool for reasoning about work
context, interactions, 5 (2), 1998
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Bas???? ???sµ?? ?deat?? s?st?µ?t??

• ??a? ßas???? ???sµ?? ??e? t? µ??f?
• ..??a s?st?µa p?? ?a ???e? t? ?, ???s?µ?p????ta?
  t??? ? p?????, ??a ?a ep?t??e? t? st??? ?.
• ?????s? ßas???? ???sµ??
• Customers
• Actors
• Transformation
• Weltanschauung
• Owners
• Environment
• G?a ?a pe????????µe s?st?µata p?? e??p??et???
  ???a, p??pe? p??ta ?a ???s??µe ta s?st?µata ta
  ?p??a e??p??et???ta?.

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?atas?e?? ???t???? p??t?p??

• ?e?????ta? ap? t? ßas??? ???sµ? ?ata???f??µe t??
  d?ast????t?te? p?? apa?t???ta? ??a t? ?e?t?????a
  t?? s?st?µat?? ?a? t?? s??d???µe.
• ???s??t??µe d?ast????t?te? e??????, ?????
  ap?fas??, s??????? p????f????? ?a? ???p???s??.
• ???????µe t? µ??t???.

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• ??µ??????a ???t???? ???t?p?? µe ß?s? t? ?eµe???d?
  ???sµ?
• ??e???? ???t?p??
• ?? s?st?µa p??pe? ?a ??e? s??p?, µ??a??sµ? ?????
  ap?fas??, st???e?a p?? a????ep?d????, pe??ß?????,
  ???a, d??at?t?ta a?t?µet?p?s?? e?t??p?a? ?a?
  ep?ß??s??, ?a? ?a e?d?af??e? ??p????
• ?e?t??s? µe efa?µ??? ?e????? ???ta??? s?st?µ?t??,
  ß??s?µ??, a?t?p???s?? ?.?p.

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???t??? st?? SSM

• Ge???? ? ???t??? p?? as?e?ta? af??? t??
  ap????f?s? µe????? µ????? t?? p??sp??e?a? st??
  ???sµ? t?? p??ß??µat?? ?a? ??? st?? ??se??.
• ?p?p????
• ? µe??d?????a p???p???te? t?? ep?te???
  s??a??es??. S???? a?t? de? e??a? ef??t?.
• ? SSM p???p???te? t? s?µµet??? ???? t??
  eµp?e??µ????. ?pa?te?ta? s?µµet????? ????t???a.
• ?as??eta? st?? ?p??e?µe????t?ta.
• ??e? ????? ??st?? ??at? apa?te? t? s?µµet???
  p????? at?µ??.

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?s??s?

• ?a efa?µ?sete t? ?e??d?????a ??µet?ß??t??
  S?st?µ?t?? ??a t? ße?t??s? t?? p??ß??µat????
  ?at?stas?? e??? ???a??sµ?? (p.?. ep??e???s?,
  p?d?sfa????? ?µ?da) t?? ep?????? sa?. ?a d?sete
• ??? p???s?a e????a t?? p??ß??µat???? ?at?stas??
• ???? ?as????? ???sµ??? t?? s?et???? s?st?µ?t??,
  ???s?µ?p????ta? t?? a????s? CATWOE
• ?a ?deat? µ??t??a(???t??? p??t?pa) ??a t???
  ßas????? ???sµ???, ?a?
• ???t?se?? ??a t? ße?t??s? t?? p??ß??µat????
  ?at?stas??

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Hard vs. Soft Systems Thinking
Hard Systems Soft Systems
??ad??as?a ??p?p???s? ?p??e?µe????t?ta
?pa?????? ?e???? ?????
Ge???e?s? Sta?e?? ß?s? p??ß?e??? ?e?????sµ???
???t??a ???????µ??? ???et???
????? t?? a?a??t? ???e? t? ??s? Facilitator
?a??de??µa ?p?st?µ????? S?st?µ???
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?fa?µ??? t?? S?st?µ???? s????? (Systems thinking)

• ? s?st?µ??? s???? µa? pa???e? ??a e??a?e??
  ?ata???s?? d?s????? p??ß??µ?t?? (?a?) st? ????
  t?? d?????s??.
• Se a?t??es? µe t?? ??ass??? t??p? s?????, p??
  e?et??e? µeµ???µ??a ?e????ta ?a? t?? a?t?e? t???
  (???a ?e????ta, s??????), ? s?st?µ??? s????
  e?et??e? µ?a ep??e???s? ?? s?st?µa p??
  ap?te?e?ta? ap? ep?µ????? a????ep?d???ta
  st???e?a.

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?fa?µ??? t?? s?st?µ???? s?????

• S?µf??a µe t?? ??as??? t??p? s?????, a?a??t??µe
  t?? a?t?e? t?? p??ß??µ?t?? p?? a?t?µet?p??e? ??a?
  ???a??sµ?? (p.?. ep??e???s?) se ?e????ta p??
  s?µßa????? st? e??te???? t?? ???a??sµ??.
• ??t? ? p??s????s? ??e? t? µe?????t?µa ?t? d?s???a
  e?t?p??e? µ?a ??s? p?? µp??e? ?a ???p????e?.
• ??t??eta, µe t? s?st?µ??? s????, ta a?t?a
  a?a??t??ta? st? es?te???? t?? ???a??sµ??, st?
  d?µ? t?? s?st?µat??. ?e t? ße?t??s? t?? d?µ??
  ep?d???eta? ? a?t?µet?p?s? t?? p??ß??µ?t??.

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??p?? s?µpe??f???? (patterns of behaviour)

• ? s?st?µ??? s???? ap?te?e? ??a ?s???? e??a?e??
  a????s??, d??t? d?af??et??? s?st?µata a?????????
  t??? ?d???? t?p??? s?µpe??f???? se d?af??et????
  ?atast?se??.
• G???????ta? t? s??s? t?? µetaß??t?? (d??. t? d?µ?
  t?? s?st?µat??) p?? p???a?e? ???e t?p?
  s?µpe??f????, µp????µe ?a e?t?p?s??µe ta a?t?a
  t?? p??ß??µ?t?? ?a? ?a ta d?????s??µe.

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??p?? s?µpe??f????

• ???et??? a??pt??? (exponential growth)
• ? a????? p?s?t?ta a????e? µe s???pe?a t??
  ep?t????s? t?? ???µ?? a???s??
• ??a??t?s? st???? (goal seeking)
• ? a????? p?s?t?ta ?pe?ßa??e? ? ?p??e?peta? t??
  ep???µ?t?? st????, ?a? st?? p??e?a s??????e? µe
  a?t??.

37
??p?? s?µpe??f????

• S??µ?e?d?? a??pt??? (?aµp???? S)
• ? a????? e??et??? a??pt??? a??????e?ta? ap?
  s?µpe??f??? a?a??t?s?? st????
• ??µat?e?d?? s?µpe??f???
• ?p?????? d?a??µ??se?? ???? ap? ??a s???e???µ???
  ep?ped?

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??p?? s?µpe??f????

• S???? s??a?t??µe ep?s?? s??d?asµ??? t??
  d?af??et???? t?p?? s?µpe??f????, ?p??
• ???et??? a??pt??? se s??d?asµ? µe ??µat?e?d?
  s?µpe??f???.
• S?µpe??f??? a?a??t?s?? st???? se s??d?asµ? µe
  ??µat?e?d? s?µpe??f???
• S??µ?e?d?? a??pt??? se s??d?asµ? µe ??µat?e?d?
  s?µpe??f???

39
Feedback or causal loop

• ?ta? ??a st???e?? t?? s?st?µat?? ?µµesa ep??e??e?
  ?a? t?? ea?t? t??, ?? s??se?? p?? a?apt?ss??ta?
  ap?te???? µ?a s??s? a??d?as?? (feedback loop ?
  causal loop)
• ??a s??s? a??d?as?? e??a? µ?a ??e?st? d?ad???
  a?t??? ?a? ap?te?esµ?t??. ?p?te?e? d??. ??a
  ??e?st? µ???p?t? ???? p????f???a? (? e?e??e???).

40
S??se?? a??d?as?? ?a? t?p?? s?µpe??f????

• ?a a?t?a t?? s?µpe??f???? t?? s?st?µ?t?? (d??. ?
  eµf???s? t?? t?p?? s?µpe??f????) e?t?p????ta?
  st?? s??se?? a??d?as?? p?? ????? ta s?st?µata
  (?et??? ?a? a???t??? a?at??f?d?t?s?).

41
Causal loop diagrams

• ???a? ??af???? a?apa?ast?se?? t?? ep?d?as?? t??
  a??d?as?? (feedback) e??? s?st?µat??.
  ?p?te????ta? ap? µetaß??t?? ?a? ß??? p??
  de?????? t?? a????ep?d?as? µeta?? t???.
• R ? positive loop (reinforcing)
• B ? - negative loop (balancing)

42
Causal loop diagrams

• ?a ß??? µe de?????? ?t? µ?a µetaß??? st?? p??t?
  µetaß??t? p???a?e? a??a?? st? de?te?? µetaß??t?
  p??? t?? ?d?a ?ate????s?. (positive feedback
  loops)
• ??t??eta, ta ß??? µe - de?????? ?t? ? µetaß???
  e??a? p??? t?? a?t??et? ?ate????s?. (negative
  feedback loops)

?a??de??µa ?? fa???µe?? t?? µeta??ste?s??
43
?a??de??µa ? µ??a??sµ?? a??d?as?? st? ??µ?sµa
e??? p?t?????
44
Negative feedback loop µe ?a??st???s?
45
?a??de??µa positive feedback loop
Reinforcing loop
?? fa???µe?? t?? ?????st?ß?da?

• S??s? a??d?as?? ?et???
• ??p?? s?µpe??f???? e??et??? a??pt???

46
?a??de??µa negative feedback loop
Balancing loop

• ?a??de??µa ???µ?s? t?? ?e?µ???as?a? se µ?a
  ??e?t???? ???ß??ta.
• ????t??? s??s? a??d?as?? -gt S?µpe??f???
  a?a??t?s?? st????.

47
?a??de??µa d?e?pe?a??s? e??as???
48
S??d?asµ?? a???t???? ?et???? feedback loops
49
Systems Dynamics

• St?? a???? t?? de?aet?a? t?? 1960, st? MIT Sloan
  School of Management ? Jay W. Forrester efa?µ??e?
  t?? ???se?? p?? ap??t?se st?? ??e?t??????
  (electrical engineering) se d?af??et???? µ??f??
  s?st?µ?t??. ?d??eta? ? ?µ?da MIT System Dynamics
  Group.
• ? ?e???a t?? ???aµ???? t?? S?st?µ?t?? µa? ß????
  st?? ?ata???s? ?a? t? µe??t? t?? s?µpe??f???? t??
  s?µp????? s?st?µ?t?? st? ?????. ?e?et? t??
  es?te???? a??d?as? (internal feedback loops) ?a?
  t?? ep?d?as? t?? ?????? p?? ep??e????? t?
  s?µpe??f??? t?? s?st?µat??.
• S?µf??a µe t? ???aµ??? t?? S?st?µ?t??, ?
  s?µpe??f??? e??? s?st?µat?? st? ????? de? e??a?
  ??aµµ???.
• O? µe??d?????a ?a? te????? µ??te??p???s??
  ???s?µ?p??e?ta? ??a t?? ape?????s?, ?ata???s?,
  ?a? a????s? s?µp????? fa???µ????.

50
Systems Dynamics

• ? ???aµ??? t?? S?st?µ?t?? ?e??e? t?? a??d?as?
  (feedback loop) ?? t? ßas??? d?µ??? st???e?? t??
  s?st?µ?t??.
• ??a ap?? s?st?µa ap?te?e?ta? ap? µ?a ?et??? ?a?
  µ?a a???t??? a??d?as? (positive and negative
  feedback loop) p?? s??d???ta? ???????.
• ? ???aµ??? t?? S?st?µ?t?? ep?t??pe? t? d?µ??????a
  µ??t???? p??s?µ???s?? ?ste ?a e?etaste? ?
  s?µpe??f??? e??? s?st?µat?? se d??f??a
  e?de??µe?a.
• ?? ?a? a????? ape?????ta? se ste???? ep??e???se??
  ??a t?? ?ata???s? t?? ß??µ??a????? d?ad??as???,
  s?µe?a ???s?µ?p??e?ta? e????? ?? te????? a????s??
  ?a? s?ed?asµ?? se ????? t??? t?µe??, p.?. st?
  ß??????a, sta ??????µ???, st? µe??t? t??
  ep??e???se?? ?a? t? µe??t? t?? pe??ß?????t??,
  µeta?? ?????.

51
Systems Dynamics

• ???e s?st?µa µp??e? ?a pe????afe? µe d??
  st???e?a
• ??? ?at?stas? (level) ?a?
• ?? ???µ? (rate)
• ?a?ade??µata
• ? ??????µ??? ?at?stas? µ?a? eta??e?a?, ? f?µ?
  e??? at?µ?? ?.?p.

52
?as??? st???e?a t?? ???aµ???? t?? S?st?µ?t??
53
(No Transcript)
54
???a?e?a Systems Dynamics

• Powersim (powersim.com), Vensim (vesim.com)
• iThink (iseesystems.com)

55
?a??de??µa p??s?µ???s?? fa???µ???? µe positive
feedback
56
?a??de??µa p??s?µ???s?? fa???µ???? µe negative
feedback
57
Te???a t?? ?????

• ? ?e???a t?? ????? ???s?µ?p??e? a???? t??
  f?s????, t?? µa??µat???? ?a? t?? f???s?f?a? ??a
  ?a µe?et?se? t? s?µpe??f??? t?? d??aµ????
  s?st?µ?t?? p?? e??a? e?a?s??ta st?? µetaß???? t??
  a?????? s???????. ? e?a?s??s?a a?t? ap?d?deta? ??
  t? fa???µe?? t?? peta???da?
• St????eta? st?? pa?at???s? ?t? µ????? µ???
  d?af???? st?? a?????? s?????e? (p.?. ????
  st???????p???s?? ?p?????sµ??) d?µ???????? µe???e?
  ap????se?? sta ap?te??sµata ?a?t???? s?st?µ?t??,
  a??µa ?a? ?ta? a?t? e??a? a?t????at???
  (?tete?µ???st???) ?a? ??? p??a??t???.
• ?at? s???pe?a, ? µa???p???esµ? p??ß?e?? t??
  s?µpe??f???? t?? s?st?µ?t?? a?t?? de? e??a?
  d??at? (p.? ?a????).

58
?pa?????? ??? s????? s?????
??a??t??? s???? S?st?µ??? s????
?????s? t?? µe??? ?e??t? t?? µe??? ?a? t?? ????
?µfas? st? d?µ? ?µfas? st?? a????ep?d?as?
?etaf??? µ??a?? ?etaf??? ???ta??? ???a??sµ??
59
?pa?????? ??? s????? s?????
??a??t??? s???? S?st?µ??? s????
?pa?a?aµßa??µe?a pe???µata ???ad???t?ta pe??pt?se??
??a??t?s? a?t??? ??a??t?s? s??p??
?fa?µ??? F?s???? ??sµ??, p??ß??µata µ??a????? ?fa?µ??? ???????a, a????p?st???? ?a? ?????????? ep?st?µe?
60
?pa?????? hard vs. soft
??s?aµpta s?st?µata ??µet?ß??ta s?st?µata
??st??? t?p?p???s? (f??µa??sµ??) ??? a?st???t?ta (?p??e?µe????t?ta)
?a?? d?µ?µ??e? µe??d?????e? ?a?a??? µe??d?????e?
??t??e?µe????? ap?de??e?? ?p??e?µe????? e?µ??e?e?
61
?pa?????? hard vs. soft
??s?aµpta s?st?µata ??µet?ß??ta s?st?µata
? ?????p?? ?? ??a? a??µa pa?????ta? ?? ?????p?? ?? s?µµ?t???? µe ap?fas?st??? ????
????? t?? a?a??t? ??d???? p?? p??te??e? ??se?? ????? t?? a?a??t? ?ata??t?? (facilitator)
??st??? µ??t??a ?saf? µ??t??a
62
??af???? ??a??t???? S?st?µ???? ???s????s??
??a??t??? p??s????s? S?st?µ??? p??s????s?
?µfas? Sta µ??? St? ????
?e??ß????? ????e?ta? ??et??eta?
St???? S??t???s? ???a??, e??????, µ???s?
?at?stas? Sta?e?? ???sa?µ?s?µ?
??e?a?t?s?a ?p?µ????? st???e?a µp??e? ?a e??a? a?e???t?ta ?p???e? a?????s?s??t?s? µeta?? t?? st???e???
S?µp????t?ta ????? ?e????
???p?? s????? ??a????sµ?? ??a??t?s?? a?t?a? - a?t?at?? ?pa???? S???es? ??a??t?s? s??p??
???ß??µa ??µ?µ???, ?µ?-d?µ?µ??? ?d?µ?t?