The Applications of Systems Science Understanding How the World Works and How You Work In It
The Applications of Systems Science
Understanding How the World Works and How You Work In It
Week 3 – Principles of Organization, Networks, & Complexity
• Boundaries
• Components can be subsystems
• Structural and functional hierarchies
• Interconnections between components at any level
• Connections are forces and flows
• A general measure of complexity is the hierarchical tree depth
Motivating Questions
• What does it mean to say that “everything is connected to everything else?” – Direct connections vs. indirect connections
– Things affect one another
• What do we mean when we say that something is complex? – Lots of different kinds of things connected
– The component things are themselves composed of smaller (and connected) things
General Organization
Environment
System of interest
boundary
inputs outputs
sources
sinks
New environment
Original system of interest
former sources and sinks now included in a larger system of
interest
New sources and sinks
New boundary
New system of interest
Generic System of Interest
Expanded System of Interest
Boundaries
concrete, regular, tight boundary
concrete, irregular, porous boundary
fuzzy, irregular, porous boundary
strong couplings
couplings
boundary components
internal component(s)
weak couplings between boundary components and external entities
etc.
“conceptual” boundary
Example of boundary mechanics
Examples of physical boundary types
Example of a boundary of choice
Systems Composed of Subsystems
Whole System of Interest
Components are
subsystems
Components
Level of the Whole System of Interest
One level down (smaller)
One level further down
Meta-Level
Component “Personalities” and Interactions - Connections
B
D E
Z
A
C
A A
D
C Z
E
B
D B
C
A
1
4
2 3 5
6
Different components with different personalities and connection potentials
Examples of Interactions and Matching
Networks of Interactions - Relations
Sparse interactions Dense interactions
Interactions: Forces & Flows
• Systems interface with their environments through interactions with other systems/entities
• Flows: Energy, materials, messages
• Forces: The usual suspects (gravity, electromagnetic)
Process/System
Sources Sinks
Energy
Messages
Low Entropy Materials
High Entropy Materials (waste)
Products
Messages
Inputs Outputs
Force Interactions
Waste Heat
Abstract Network Representation
inputs outputs
decomposed node
Graph theory mathematics can be used to answer structural and functional questions about this network (a directed graph)
Interesting Properties of Evolving Networks
Hubs: Small World Phenomena
Cliques: Auto-organizing Phenomena
Structural & Functional Hierarchies
subsystems
inputs outputs
larger system
coupling strengths high
coupling strengths medium
coupling strengths with other systems
low to high
System
Subsystems & interconnections
Components & interconnections
Complexity
Relational complexity
Compositional complexity
Simplicity
Structural complexity
A B
C D
A Hierarchy of Composition
stable combinations and free atoms
strong/stable interactions
transient combinations of stable components
whole system-of-interest level
relatively stable complex component level
free atoms level – maximum entropy
Hierarchic System
L-0
L-1
L-2
L-3
L-4
weak/transient interactions
increasingly complex combinations and free atoms
Levels of Organization
Chemical Atomic Level (L-0) Carbon, Hydrogen, Nitrogen, Oxygen,
Phosphorus, Sulfur (CHNOPS) – plus trace elements
Chemical Molecular Level (L-1)
Amino acids, Fatty acids, Nucleic acids, Carbohydrates – sundry other low weight molecules
Structural Molecular Level (L-2)
Proteins, RNAs, DNAs, Fats, Polysaccharides, etc.
Functional Unit Level (L-3)
Ribosomes, Mitochondria, Chromosomes, Golgi apparatus, etc.
System Level (L-4)
Cell
Increasing combinations
Increasing consolidation
Seminar Questions - Organization • How can we characterize the relations
between hierarchical organization, network structures, and component interactions?
• What are the characteristics of the “boundary” of a corporation?
• What are some examples of stuffs that “flow” between systems in the real world?
• What exactly do we mean by the depth of a hierarchy of organization and why is it a reasonable index of complexity?