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 Kermack-McKendrick-Model.

The whole population is separated into three stocks(→modelOutput):

• The Susceptible (S) population that is not immune and may be infected.


• The Infected (I) population that is infected and infectious.


• The Removed (R) population can neither be infected nor spread the disease.

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 1in the Diffusion component.

Simulation Results

Notes

• As in the example →SimpleProductionChainIII we need to use an expandable connector (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.

• Adjusted modelSettings and modified plot in v2.0.0.