Support material for workshops #231 (2022-07-22T08:30+02:00) and #232 (2022-07-22T10:30+02:00) at the International System Dynamics Conference 2022 in Frankfurt, Germany.

In this workshop, we want to introduce object-oriented modeling using pre-build components for System Dynamics. The participant will start by creating a simple System Dynamics model similar to building structures using LEGO blocks. They will learn to plot the variables from different components and quickly iterate over various designs by changing the model parameters. They will then document their plots(results) by adding plot markers, captions, and plot labels. Finally, they will learn to store the plot in the model for future reference.

Business Simulation Library developed by Guido Wolf Reichert will be used for this workshop. This free library supports modeling & simulation in the social sciences and ecology. It follows the widespread System Dynamics metaphor and modeling approach introduced by Jay W. Forrester. Unlike existing approaches, it makes use of Modelica's acausal connectors to better distinguish material/mass flows from instantaneous information signal flows (causal connections). The approach has the additional benefit of allowing the modeler to build rather compact models in a fast and reliable fashion.

The participants will then expand their simple model by adding pre-built components. This will make them appreciate the importance of using reusable components. They will learn to read the documentation of these pre-built components and understand how to use them. Finally, they will learn to document their own models.

Participants will use Wolfram System Modeler for this workshop. Wolfram System Modeler is an easy-to-use, next-generation modeling and simulation environment for cyber-physical systems. It is based on the Modelica language which is an open standard language. The participants will receive a 6-month trial so that they can create and test models at their leisure. Participants should bring a laptop.

Workshop Presentation

This workshop is designed to follow the workshop on "Introduction to object-oriented hierarchical modeling using pre-built components". The participants will learn to do custom analysis on their models using the Wolfram Language.

The Wolfram Language is a general multi-paradigm programming language developed by Wolfram Research. It emphasizes symbolic computation, functional programming, and rule-based programming and can employ arbitrary structures and data.

The participants will start by plotting the results of their object-oriented models (which they would have created in the previous workshop) in the Wolfram Language. They will then create a simulation object that can be queried to obtain values of the variables for the entire simulation. These values can then be passed to the relevant Wolfram language functions for analysis such as optimization, calibration, control design and many more. The participant will also learn to simulate multiple scenarios in parallel and understand the parameter sensitivities.

This will be followed by a session where the participants will learn to create automated tests using the Wolfram Language to keep their models updated. They will follow a step-by-step process to set up the test infrastructure for their simple models and learn the best practices.

Finally, they will learn to create custom dashboards. They will learn how to create custom plots and document the model parameters with relevant descriptions. They will learn about different control objects that can be used to improve the user experience. Some common mistakes and tips-and-tricks will also be covered.

They will then deploy the dashboard in the free Wolfram cloud. Through this process, they learn how to collaborate with others and learn how to publish the dashboard on the web for public access. Participants should bring a laptop.

Workshop Notebook

Copyright © 2022 Guido Wolf Reichert Licensed under the European Union Public Licence (EUPL), Version 1.2 or later (the "License")

You may not use this work except in compliance with the License. You may obtain a copy of the License at:
https://eur-lex.europa.eu/eli/dec_impl/2017/863/oj

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