
“Thinking in Systems: Primer” is a great resource that can help you whether you are beginning, or have already started your systems thinking journey.
Meadows helps us understand what a system is. “A system is an interconnected set of elements that is coherently organised in a way that achieves something”[1]. “Once we see the relationship between structure and behaviour, we can begin to understand how systems work”[2]
She also helps us understand the elements of a system. “A stock is the foundation of any system. Stocks are the elements of the system that you can see, feel, count or measure at any given time” [p17]. “Stocks change over time through the actions of a flow[3]. “A feedback loop is formed when changes in a stock affect the flows in and out of that same stock”[4]. A balancing feedback loop stabilises the stock level [5]. A reinforcing feedback loop can be a vicious or virtuous circle because it amplifies and reinforces[6].
The book takes the reader on a visit to the “Systems Zoo”, which contains many examples of systems and draws lessons from them. Meadows also shows us where we can leverage a system.
Donella Meadows writes that we should “stay humble – stay a learner”[7]. That you should “expose your mental models to the light of day”[8], make them as rigorous as possible, test them against supported evidence and scuttle them if they are no longer supported.
There are useful appendices to the book that include a glossary and a summary of systems principles.
“The systems thinking lens allows us to reclaim our intuition about systems and
- Hone our abilities to understand parts
- See interconnections
- Ask “what if” questions about future behaviours and
- Be creative and courageous about system design” [9]
To help my learning, I used the book to create systems diagrams of the systems for managing bugs that I am aware of.
The first diagram shows a system in which managers encourage the reporting of bugs because they are dissatisfied with the quality of the product, and at other times, they discourage the reporting of bugs by stating that no bugs will be fixed this quarter, so that work is focused on a new feature. The changing perceived value of submitting a bug report creates a reinforcing loop that amplifies changes in the numbers of reported bugs.
This system diagram enables me to see the faults in this system, understand the Stock of Bugs, to see its interconnection with the perceived value of submitting a bug report, to ask “what if” there was stable feedback about bugs to the development team, and to think about how to design a system where the development team did not have to manage the Stock of Bugs.

The second diagram shows a company which asked its developers to fix ten bugs each iteration, which is shown as a balancing loop that stablises the Stock of Ten Bugs.
This system diagram enables me to understand a small Stock of Bugs as an input into development team planning, to see its connection with software failures, to ask “what if” we reduced the number of software failures, and to think about what the Stock of Ten Bugs represents.

I read Thinking in Systems with the Profound Book Club, and would like to thank the members of the club for the useful discussions that we had.
Thinking in Systems is, as its title says, “a primer”; it is a great resource that will help you on your systems thinking journey.
References
[1] Thinking in Systems: A Primer by Donella Meadows (2008, p. 11)
[2] Thinking in Systems: A Primer by Donella Meadows (2008, p. 1)
[3] Thinking in Systems: A Primer by Donella Meadows (2008, p. 18)
[4] Thinking in Systems: A Primer by Donella Meadows (2008, p. 25)
[5] Thinking in Systems: A Primer by Donella Meadows (2008, p. 27)
[6] Thinking in Systems: A Primer by Donella Meadows (2008, p. 31)
[7] Thinking in Systems: A Primer by Donella Meadows (2008, p. 180)
[8] Thinking in Systems: A Primer by Donella Meadows (2008, p. 172)
[9] Thinking in Systems: A Primer by Donella Meadows (2008, p. 6)
Additional Links
- The Donella Meadows Project
- Donella Meadows YouTube Channel
- Tools that can be used to draw systems diagrams:






