A teaching script will train you in the graphical integration of simple systems with feedback.

After completing this worksheet, you should be able to sketch the change of a stock over time depending on flows that are influenced through a feedback loop.

For more exercises like this in addition to valuable introductory remarks, have a look at Choudhari (1996).

Texts you need for this reading prompt:

• Whelan (1996)
• Zhu (2001)

The first reading will cover positive feedback loop. It starts with an introduction on positive feedback and presents a simple model. Afterwards, it is explained how the behavior of a level in a single positive feedback loop can be estimated.

Please read Whelan (1996), p.1-7 now and try out the exercises, too.

As stated by Whelan (1996), the four steps on estimating the change of a stock in a simple positive feedback are:

• Definition of the starting point
• Definition of the positive feedback loop
• Definition of how the stock will grow
• Calculation of the doubling time of the exponential growth

Let's have a look on negative feedback.

Please read Zhu (2001), p.1-14 now and try out the exercises.

As stated by Zhu (2001), the five steps on estimating the change of a level in a simple negative feedback are:

• Definition of the starting point
• Definition of the negative feedback loop
• Definition if the stock will grow asymptotic or to an equilibrium
• Definition if you are above or below the target value
• Identification of the goal/gap structure of the feedback loop
• Calculation of the halving time