.BusinessSimulation.CausalLoop

Information

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This package contains high-level classes (i.e., wrappers) that allow to quickly set up dynamic models in a Causal Loop Diagram (CLD) fashion. Unlike conventional CLD such models can immediately be simulated and analyzed.

A typical workflow in an "Agile Dynamic Modeling" setup would be to quickly establish a first working model using the most relevant variables as starting points and consider them to be stocks/levels. Exogenous processes of change and/or control next to simplified relations between the variables—defined by elasticities or proportionalities—will then give rise to dynamic behavior.

Such a preliminary model can be made more expressive by introducing lookups to modify constant coefficients (e.g., factors of proportionality) thus making the models more nonlinear. As van Zijderveld [24] has shown, such models may even suffice in situations of tight budgets or lower stakes.

True to the Agile paradigm, we may start out with a preliminary, working model and replace any of its parts by more elaborate models as needed. Such a gradual approach to modeling is the sweet spot of object-oriented modeling in Modelica.

Notes

Since not all component names are visible in the diagram display for CausalLoop classes the following table shows the defaultComponentName for the main classes of the package:

See also

To see the components of this package at work, have a look at these example models:

• HealTheWorld


• SoftwareReleaseProject

A short video presentation (12 min) introducing quantitative causal loop diagramming can be found here.

Copyright © 2021 Guido Wolf Reichert
Licensed under the EUPL-1.2 or later

Contents

Name	Description
SimpleInformationLevel	Information level for CLD-like modeling
SimpleMaterialStock	Information level for CLD-mapping
Performance	Evaluation of a stock on a [0,1] scale
InputControl	Directly set information using a ramp input profile
SimpleControl	Directly influencing a stock to keep it at setpoint value
PID_Control	Directly influencing a stock to keep it at setpoint value
ExponentialChange	Exponential growth or decline process
LinearChange	Process of growth or decline at given rate
LogisticGrowth	S-shaped logistic growth process
Elasticity	Fractional rate of change is proportional to that of the influencing stock
ElasticityDelayed	Process driven by elasticity and additional exponential delay
Proportionality	Rate of change is proportional to that of the influencing stock
ProportionalityDelayed	Process driven by proportionality with additional exponential delay
ForceToInputValue	Flow is obtained as closing the gap to input value
ForceToStockValue	Flow is obtained as closing the gap to input stock value
ExponentialDelay	Exponential delay of input flow
PipelineDelay	Fixed or pure delay of input flow
ComplexInteraction	Interaction with linear and nonlinear terms
UnidirectionalFlow	Interaction with linear and nonlinear terms
SplitFlow	Splitting a flow into n flows
Lookup_JPositive	Positively sloping s-shaped lookup
Lookup_JNegative	Negatively sloping s-shaped lookup
Lookup_SPositive	Positively sloping s-shaped lookup (centered at origin)
Lookup_SNegative	Negatively sloping s-shaped lookup (centered at origin)
Lookup_Table	Table-based lookup with manual input of the interpolation table
Lookup_TableOnFile	Table-based lookup given on file
Aggregation	Generalized mean function for multiple stock information inputs
StockInformation	Provide amount in stock information
RateInformation	Provide rate of net flow information
Aggregation_Info	Generalized mean function for multiple information inputs
Total	Sum all inputs
Product	Multiply all inputs
LoopIndicator_CW	Loopindicator for clockwise feedback loop
LoopIndicator_CCW	Loopindicator for counter clockwise feedback loop
MatFlowIndicator	Directional indicator for material flows in a diagram
InfoFlowIndicator	Directional indicator for information flows in a diagram
SketchVariable	Class to be used for comments or sketch variables

Revisions

• Introduced in v2.0.0.