How this Guide is organized

This System Dynamics Learning Guide (SDLG) provides a hands-on introduction to using systems thinking – system dynamics in particular – to address real-life complex problems.  The guide corresponds to anywhere from 7-12 weeks of an undergraduate, 3-credit course (depending on how much of the material is used).  The remainder of the course could be devoted to a large modeling project.

The guide is both experiential and context-based.  It is experiential because students will learn how to build system dynamics models rather than simply hearing or reading about them. The System Dynamics Learning Guide is context-based because the guide is based on a real-life complex problem involving a system of interacting forces and stakeholders whose collective behavior can defy intuition and common sense. Solving such problems can be very difficult!  Through reading the material, completing the exercises (called Action Items), and participating in activities and discussions during class, students will learn how to build and use system dynamics models to aid decision making in the face of such complexity.

By completing the readings and activities in this guide, students will be able to:

1. Distinguish systems thinking from more conventional approaches.
2. Identify those characteristics that cause problems to be complex.
3. Explain why solving complex problems requires a system-based approach.
4. Use Causal Loop Diagrams (CLD’s) and system storytelling to describe the system behind a problem.
5. Use stocks, flows and system modeling software to build a running computer simulator to help make better decisions.
6. Explain how the feedback structure in the system gives rise to its behavior.
7. Use system dynamics models to help a decision maker who must contend with competing stakeholder interests.
8. Communicate their analysis in ways that are accessible to decision makers and stakeholders.

This guide gives students an introductory exposure to the ways of thinking, modeling skills, and analysis and communication skills that are central to system dynamics. Because of their introductory nature, this guide will not cover some more sophisticated topics, such as:

• How to conduct group modeling activities aimed at acquiring domain knowledge, building alignment, and creating from scratch a modeling framework.
• Parameter tuning and model validation.
• Sophisticated model analysis methods (i.e., optimization, sensitivity analysis, etc.).

The guide is organized as follows.

Chapter 1: Experiencing the Challenge (week 1)

Students will assume the role of a person facing a significant decision-making challenge:  they have to choose a course of action to fix a particular real-life (or very realistic) problem. Things are complicated because the problem is rooted in a complex system involving multiple feedback loops, delays between action and effect, competing natural forces, and stakeholders with contradictory goals and values. This means that simplistic efforts to correct the problem will often lead to surprising, even disastrous outcomes.

The decision-making challenge is based on an historical real-life problem. The students are given the same kind of information typically available to those who have worked on problems like this. They will then be placed in the role of decision maker to try and affect the future in desirable ways.

Their actions will be implemented through a computer model that mimics the kind of behavior in the real-life system. Based on what actions are chosen, students will watch as the likely outcomes of those choices unfold. They are often very surprised by what happens!

Students finish this stage of the guide by presenting the results of their actions to all the stakeholders and explaining how this affects each of them.

The purpose of this section is to expose students to the pitfalls of using human intuition to tackle such problems and why a systems approach is needed.  They will get another chance with this problem by progressing through the rest of the guide!

Chapter 2: Developing a New Way of Seeing: Systems Thinking (weeks 2-3)

Here the guide helps students to back up and take a fresh look at the problem in Chapter 1 by employing systems thinking. They will learn how to see the roots of the problem in a new way — not in terms of individual actions or events, but in terms of evolving behavior over time that is created by a system whose structure is perfectly designed to create and sustain the problem.  They will learn to describe that system using feedback loops and causal loop diagrams and to tell system stories that help stakeholders “see” how the structure of the system creates the problematic outcomes.

Chapter 3: Simulation Basics ― How a System Dynamics Simulator Works (week 4)

To effectively understand and build running system dynamics models, students need to grasp the fundamental principles behind how these programs operate. This brief section introduces students to how a simulation program progresses step by step through time, updating all system variables at each step. It also explains the importance of the time step (DT) in influencing both the simulation’s performance and its numerical accuracy. The mathematical concepts are kept simple, requiring only basic algebra and straightforward calculations.

Chapter 4: Introduction to System Dynamics Model Building (weeks 5-8)

Having identified the system is not enough! That’s because predicting the behavior of such feedback-rich systems cannot be done without the help of a computer. So, in this part of the guide, students will learn how to build running models of complex systems. They will learn to use modeling software to construct the basic building blocks that will make up the model. We use Stella Architect® as the modeling platform because of its easy accessibility, and its capacity to develop useful interfaces.  Throughout this section, students will begin to develop skills in system storytelling to explain how the feedback structure of the system creates its evolving and possibly complex behavior over time. Students will do this by building user interfaces in Stella Architect® and constructing interactive system stories.  This section culminates with students building a (somewhat simplified) version of the original simulator they used in the first section of the learning guide. This “closes the loop” for the students by showing them that (1) the complex behavior they experienced in Chapter 1 is the result of a constellation of interacting feedback loops, and (2) they can build models that mimic this kind of behavior.

Chapter 5:  Using Models with Decision Makers (weeks 9 -10)

Now, given the basic model building and storytelling skills developed in Chapter 4, the System Dynamics Learning Guide exposes students to both the power and the challenge of using system dynamics models to help decision makers envision system-based ways to impact the future.  In this section, students are introduced to the role of stakeholders in complex problems and how those interests can sometimes be in conflict, so that, what constitutes a “win” for some stakeholders can result in “loss” for others.  Students will learn about the use of a balanced scorecard – a carefully designed collection of behavior over time graphs that show different aspects of how the system might respond to possible interventions.   This scorecard is designed so that decision makers can evaluate and weigh the interests of different stakeholder groups. In addition, through the insights gained through thoughtful system storytelling, and through simulation of different scenarios, decision makers and all stakeholders can better understand what sorts of futures are possible, which are impossible, and why.  In this way, students learn how complex problems seldom have a “correct” solution, but that they often respond in ways that present tradeoffs between competing interests ― tradeoffs that should be understood and weighed.

Chapter 6:   Final Model Building Project and Presentations (weeks 11-12)

The learning guide ends with descriptions of modeling projects that students can tackle in order to apply what they’ve learned. Each project covers about 2-3 weeks of work and requires each student to develop a working model, interface, and analysis for a decision maker and accompanying stakeholders. Each modeling problem is built around a realistic decision-making scenario with a client (decision maker) and stakeholders whose concerns must be addressed. By completing the project, students gain an opportunity to combine into one coherent effort all the building blocks of systems thinking, model building, and analysis covered in the earlier sections.

Modeling Challenges: Practice in Applying Concepts

This guide works best when used in an active learning format. For several years, we have used a “flipped” classroom structure, in which the students complete the readings, watch very brief online lectures, and complete some simpler preparatory exercises prior to class.  The Modeling Challenges, found throughout the text are central to this strategy. Some of these are marked in the text as follows:

Modeling Challenges: these are good candidates to work on during class or as homework exercises.  Some of the these are marked as follows: