CAUSAL LOOP MODELLING
Professor Ockie Bosch
Dr Nam Nguyen
Causal Loop Diagrams (CLD)
Bayesian Belief Networks (BBN)
Evolutionary Learning Laboratory (ELLab)
Behavior Over Time (BOT)
Systems Archetypes (SA)
Sensitivity Model (Basis of Ecopolicy)
Viable System Model
Stock and Flow Diagrams
Systems Dynamic Models and more…
Systems Thinking Tools
© Professor Ockie Bosch and Dr Nam Nguyen
Climate Change
Carbon Emission
Water Shortage
Land Use
Environment
Biodiversity
Energy Crisis
Food Crisis
Economic Growth
Globalisation
Sustainability
Social Dislocation
Poverty
Human Health
Animal Health
Food Safety
Current Issues in the Media
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These different issues can not be regarded as single entities that can be dealt with in isolation from each other
What are the relationships/interactions between these issues/variables?
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Interconnected?
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The Environment Loop
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The Environment Loop
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Population Loop Added
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Agriculture Loop Added
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Biofuel Loop Added
Modified from Maani and Nguyen (2009)
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AN INTEGRATED SYSTEMS MODEL
Causal Loop Diagrams (CLDs) provide:
‘… a framework for seeing interrelationships rather than things, for seeing patterns of change rather than static snapshots’.
Peter Senge (2006)
© Professor Ockie Bosch and Dr Nam Nguyen
Definition
Variable is a condition, state, action, or decision which can influence, and can be influenced by, other conditions, states, actions, etc.
A variable can be quantitative (e.g., number of employees, kilograms of production, business profit, etc.) or it can be qualitative (e.g., values, motivation, reputation, feelings, respect, etc. ).
© Professor Ockie Bosch and Dr Nam Nguyen
Basic Elements of Causal Loop Diagrams (CLDs) -Variable (adapted from Maani and Cavana, 2007)
• An arrow indicates a causal relationship or change in the state of two variables.
Bank balance
Interest
• S (or +) indicates change in the Same direction.
• O (or -) indicates change in the Opposite direction.
© Professor Ockie Bosch and Dr Nam Nguyen
Basic Elements of Causal Loop Diagrams (CLDs) -
Arrow (adapted from Maani and Cavana, 2007)
Interest
Bank balance
S (+)
Expenditure
O (-)
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Higher Interest
Lower Interest
Higher Bank balance
Higher Expenditure
Higher Savings
Lower Savings
Lower Expenditure
Lower Bank balance
}
}
S (or +)
O (or -)
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How to decide on the sign?
Feedback is a process in which outputs from a system affect the inputs
Feedback loops arise when a sequence of interactions form a closed loop:
A-B-C-A:
C
B
A
© Professor Ockie Bosch and Dr Nam Nguyen
Feedback (adapted from Maani and Cavana, 2007)
Reinforcing Loop (R)
Positive feedback
The R-loop represents growing or declining actions
Balancing Loop (B)
Negative feedback (counteracting)
The B-loop seeks stability or return to control, or
aims for a specific target
+
-
© Professor Ockie Bosch and Dr Nam Nguyen
Loop Types (adapted from Maani and Cavana, 2007)
InterestSavings
Balance
S
S
R
Virtuous CycleTime
Savings
Balance
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Example of a Reinforcing Loop (adapted from Maani and Cavana, 2007)
Hiding Errors /
Mistakes
Incidence of Poor
Quality
Management
Punitive Action
Fear of Blame /
Punishment
R
S
S
S
S
Quality
Time
Vicious Cycle
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“Quality Problem” - A Vicious Cycle (adapted from Maani and Cavana, 2007)
Nguyen & Bosch (2013). Using Systems Thinking to Identify Leverage Points for Sustainability. Systems
Research & Behavioral Sciences, Vol.30, No.2, pp 104-115.© Professor Ockie Bosch and Dr Nam Nguyen
Example of Balancing Loops
1. Using logic or intuition to identify the nature of the loop: growing or declining action (R), counteracting process (B).
2. Tracing the loop variable by variable: start and end with the same verb (R), with the opposite verb (B).
3. Counting the number of ‘O’ (or ‘-’ sign) in the loop: zero or even number (R), odd number (B).
© Professor Ockie Bosch and Dr Nam Nguyen
Differentiating between a ‘R’ and B’ (adapted from Maani and Cavana, 2007)
Rule 1: Know your boundaries
Rule 2: Start somewhere interesting
Rule 3: Ask ‘What does this drive?’ & ‘What is this
driven by?’
Rule 4: Use nouns, not verbs
Rule 5: Don’t use terms such as ‘increase in’ or
‘decrease in’
Rule 6: Don’t be afraid of unusual items
Rule 7: Do the ‘s’ and ‘o’ as you go along
Rule 8: A good diagram must be recognised as real
Rule 9: Don’t ‘fall in love’ with your diagram
Rule 10: No diagram ever ‘finished’© Professor Ockie Bosch and Dr Nam Nguyen
Rules for drawing CLDs (adapted from Sherwood, 2002)
A dynamic systems model of the Afghanistan conflict(The New York Times, April 26, 2010, retrieved from http://www.nytimes.com/2010/04/27/world/27powerpoint.html?_r=1) © Professor Ockie Bosch and Dr Nam Nguyen
But, this might be too much!
o Services
o Infrastructure
o Waste*******
o Hotels , Restaurants*****
o Attraction of CB Island
o Access to markets
o Investment in agriculture
o Information and communication
o Misuse of NR******
o Health
o New construction
o Tourism pollution*******
o Agricultural pollution
o Available underground water******
o Number of tourists
o Other pollution sources
o Use of underground water
o Tourism revenue*******
o NR conservation*******
o Livelihood of Commoner
o Life expectancy
o Governance structures***
o Policies
o Poverty*******
o Educated population
o Lack of Integrated Planning******
o NGOs
o People's awareness
o Social evils/crime
o Cultural values
o Population*******
o Immigration
o GDP per capita
o Tourism Development******
Waste
Water
Poverty
Tourism
© Professor Ockie Bosch and Dr Nam Nguyen
Causal Loop ModelingStep1. Gathering mental models to identify variables for the sustainable
development of Cat Ba Island, Vietnam
Number of tourists
Tourism revenue
Hotels , Restaurants
Tourism DevelopmentWaste
Tourism pollution
Attraction of CB Island
Use of underground water
Available underground water
BiodiversityLivelihood of Commoner
Misuse of NR
NR conservationGDP per capita
Agriculture revenue
Investment in agriculture
Information and communication
Access to market
Poverty
Health
Population
Educated population
Life expectancy
Governance structure
Other income Sources
Social evils/crimeNGOs
Infrastructure
Services
Lack of Integrated Planning
PoliciesStudent population
Cultural values
Agricultural pollution
People's awareness
Immigration
Food safety
New construction
Other pollution sources
Step 2: Move variables around until clear themes are appearing
© Professor Ockie Bosch and Dr Nam Nguyen
Step 3: Systemic Structure (of CAT BA Biosphere) after variables have been linked with arrows
Attraction of
CB island
Number of
tourists
Service quality
Biodiversity
Tourism
pollution
Use of
underground
water
Available
underground
waterWaste
Tourism
revenue
Hotels and
Restaurants
Agriculture
pollution
Infrastructure
Other pollution
sources
New construction
Agriculture
revenue
Investment in
agriculture
Access to
market
Information and
communication
GDP per
capita
Livelihood of
Commoner
Misuse of
NRNR
conservation
Food
safetyHealth
Life expectancyImmigration
PopulationStudent
population
Educated
population
Poverty
Cultural
values
Social
issues
People’s
awareness
Tourism
development
Lack of Integrated planning
NGOs Governanc
e structure
Policies
© Professor Ockie Bosch and Dr Nam Nguyen
Develop a CLD around an area of your own interest:
1. For Educational Purposes: You can use Vensim software (Download from: http://vensim.com/download/ (Click on Free Download)
2. In the Think2Impact Package: You can draw links between variables directly on the “Whiteboard” in the section on Developing a Systems Model (Vensim not required)
© Professor Ockie Bosch and Dr Nam Nguyen
PRACTICAL EXERCISE to draw CLDs