SIRClassical epidemic model by Kermack and McKendrick 
This information is part of the Business Simulation Library (BSL).
The SIR model is a classical approach in mathematical epidemiology to study the spread of infectious diseases. The model goes back to William Ogilvy Kermack and Anderson Gray McKendrick [23] and is also called KermackMcKendrickModel.
The whole population is separated into three stocks(→modelOutput):
As in the example →SimpleProductionChainIII we are using the →Diffusion component to model social diffusion, e.g., spread by contact. The transmissionRate
(β in the mathematical literature) is also sometimes called the effective contact rate which helps to understand why we have set the adoptionFraction
to 1
in the Diffusion
component.
inputDiffusion
) at the scope of the model to establish connections for inputs to becoming_infected
in compliance with Modelica specifications. SystemModeler will assist connections with a drop down list making this rather convenient.baseReproductionNumber 
Value: 2.5 Type: Dimensionless Description: Value of constant output (R0.value) 

infPeriod 
Value: 432000 Type: Time (s) Description: Length of the infectious perid (infectiousPeriod.value) 
n 
Value: 3 Type: Integer Description: Order of the exponential delay (infected.n) 
modelOutput 
Type: ModelOutput Description: The model's main output 


inputDiffusion 
Type: DataInPort Description: Collected (named) input for the infection process 
modelSettings 
Type: ModelSettings 


susceptible 
Type: MaterialStock Description: Population in the susceptible stage of the disease 

removed 
Type: MaterialStock 

infected 
Type: DelayN Description: Population in the infectious stage of the disease 

becoming_infected 
Type: Diffusion Description: The infection is spread by a process of social diffusion 

being_removed 
Type: OutflowDynamicStock 

infectiousPeriod 
Type: ConstantConverterTime Description: Time interval during which an individual is infectious 

R0 
Type: ConstantConverter Description: Basic reproduction number for the infectious disease 

transmissionRate 
Type: Division Description: Effective contact rate 
modelSettings
and modified plot in v2.0.0.