1. Systems & Informationlamspeople.epfl.ch/balabko/Professional/Systemic_Thinking... · 2004. 5....
Transcript of 1. Systems & Informationlamspeople.epfl.ch/balabko/Professional/Systemic_Thinking... · 2004. 5....
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1. Systems & Information
Alain Wegmann Institute for computer Communications and Applications
ICA - DI - EPFL
CH-1015 Lausanne, Switzerland Tel: ++(41) (21) 693.4381; fax: ++ (41) (21) 693.4701
[email protected] http://icawww.epfl.ch
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Table of Contents
• Systemic Approach and System Theory
• Enterprises and Systems
• Information Systems
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Systemic Approach
“The systemic approach should, from invariant, properties and behaviors of complex systems, lead to general rules helping to better understand systems and to act on them”
J. de Rosnay
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Systemic Approach / History
Julian Bigelow (engineering) Arturo Rosenblueth (neurophysiologist)
Walter Pitts (math)
J. Lettvin (physiologist)
Warren McCulloch (neuropsy) Jay Forrester (engineering)
Servo-mechanism
laboratory
1950 1960 19701940 Cybernetic Bionic Systems
Josian Macy Foundation
W. Mc Culloch (neuropsy)
J. von Neumann (math)
General Systems Society
L. Von Bertalanffy (biologist)
A. Rapoport (mathematician)
N. Raschewsky (biophysics)
Norbert Wiener (math)
action
effect
analysis
correction
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Systemic Approach / History 1940: feedback / finality (cybernetic)
1950: memory / shape recognition / adaptive systems (bionic)
1960: cybernetic, system theory – enterprise/society/ecology
Machine Organisme
Machine Organisme
Machine Organisme Entreprise Society Ecosystem
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Systemic Approach
SYSTEMIC APPROACH
=
CYBERNETIC
+
SYSTEM THEORY
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System Components Structural Elements: • Limits • Elements (people, organization, computers, agents, …) • Reservoir (reserve of energy, information, material, $, etc…) • Communication network
(means of exchange for energy, information, material, $, etc…)
Functional Elements: • Flow (of energy, information, material, $, etc…) • Gate (= control mechanism) • Delay (due to differences in speed of transmission) • Feedback loop (positive and negative)
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Cybernetic
“the art of managing and driving very complex systems”
N. Wiener
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Feedback Loop action
effect
analyse
correction
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System Theory
“a set of objects and relations between these objects and
between their attributes”
A.D. Hall & R.C. Fagen
Definition of System (1956)
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System Taxonomy CLOSED SYSTEM – system totally independent from its environment OPEN SYSTEM – system in constant relations with its environment Note: the term COMPLEX SYSTEM is defined as having:
• Variety of elements • Hierarchical levels • Multiple relations between elements • Non - linearity
energy entropy System
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Open System Properties Open systems have the following properties:
TOTALITY – the whole is more than the sum of its parts.
FEEDBACK – the system behavior is based on its components interactions;
EQUI-FINALITY – the system finality is determined not only from the initial
conditions but also from the nature of the processes.
Note: The term HOMEOSTASY reflects the existence of feedback mechanisms minimizing changes and
improving stability.
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System Model of Complex Systems (1)
1. System identified
2. Active system
3. Regulated system
La modélisation des systèmes complexes
Jean-Louis le Moigne
Dunod, ISBN 2-04-019704-4
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System Model of Complex Systems (2)
5. System decides its behaviour
Decision 4. System informed on its behaviour
6. System has memory
Decision
Information
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System Model of Complex Systems (3)
7. System synchronizes its action plans
Decision
Information
8. System invents new decisions
Invention
Selection
Information
Information
9. System knows its finality
Finality
Invention
Selection
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Exercice Give real examples of:
1. Active system .......................................
2. Regulated system .......................................
3. System informed of its behaviour .......................................
4. System decides its behaviour .......................................
5. System has memory .......................................
6. System synchronizes its action plans .......................................
7. System invents new decisions .......................................
8. System knows its finality .......................................
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System Pattern
info
data
goal
Memory Knowhow Planning
Value creation process
Data collectionImprovement process
Organization's goals
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Use of the System Pattern
info
data
goal
Each key business process
has a system pattern
around it !
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Enterprises and Systems
supplier customerValue Creation (Front Office)
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Corporate System
supplier customer
back office
information
data
corporateplan
value creation(front office)
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Development/Manufacturing Processes
supplier customer
back office
information
data
corporateplan
value creation(front office)
Product Development
Product Manufacturing
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Development/Manufacturing Systems
supplier customer
back office
information
data
corporateplan
value creation(front office)
Product Manufacturing
Product Development
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System Implementation
info
data
goal
Tools Corporate Design Mfg.
Goal Info Value Creation Data Improv-ement
? ? ?? ? ?? ? ?
? ? ?
? ? ?
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Information System
Management
Organization
Technology
Information System
BusinessSolution
(c) Management Information Systems
K. & J. Laudon, Prentice Hall
ISBN 0-13-213778-X
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Information System Definition (2)
INFORMATION SYSTEM – set of interrelated components that collect, process,
store and distribute information to support decision making and control in the
organization.
BUSINESS SOLUTIONS - organization, technology and processes bringing a
business benefit / competitive advantage to an entity / corporation.
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ORGANIZATION - an organization coordinates work through a structured
hierarchy and formal, standard operating procedures. Organizations are
composed of production workers, data workers, and knowledge workers.
MANAGEMENT – define strategies, allocate resources and coordinate work to
achieve strategies. Senior managers define long-term plan and activities,
middle level managers implement these plans, and operational managers
monitor and drive daily implementation.
TECHNOLOGY – tools and communication/integration technology used to
develop information systems.
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Bibliography • Le Macroscope
Joël de Rosnay Points / Essais ISBN 2-02-004567-2
• La modélisation des systèmes complexes Jean-Louis le Moigne Dunod ISBN 2-04-019704-4
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• Ludwig Von Bertalanffy General System Theory Braziller, New York 1968
• Management Information Systems
K. & J. Laudon Prentice Hall ISBN 0-13-213778-X
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Appendix: Systemic Approach ANALYTICAL APPROACH – investigate system by reducing it to simple and
independent objects with minimal interactions.
SYSTEMIC APPROACH – analysis of the system as a whole, taking into
consideration its complexity and its dynamic.
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Analytical Vs. Systemic Approach
Analytic Approach Systemic Approach
Focus on isolated elements Focus on element’s interactions
Focus on type of interactions Focus on effects of interactions
Care of details Care of global perception
Modify one variable at a time Modify group of variables
T independent, reversibility T dependent, irreversibility
Validation by proof Validation by observation of reality
Good for linear phenomena Good for non-linear phenomena
Mono-discipline Trans-disciplines
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Systemic Approach The systemic approach uses the following 3 steps (J. de Rosnay):
SYSTEM ANALYSIS – identification of system’s limits, important components and interactions;
SYSTEM MODELING – system modeling based on system analysis; establishment of causality links and interactions between objects; SYSTEM SIMULATION – study of the time behavior of the system
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Systemic Modelisation
Finality Environment
Evolution
Structure
Activity
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Modeling Hypothesis - The object to model has to have at least one known project
(TELEOLOGY hypothesis)
- The object to model must be described in its totality (way it is
structured, way it operates and way it evolves) (STRUCTURALIST
hypothesis)
- The object to model is open to the external environment (even if it can
be only partly described).