Systems Thinking (Overview)

Yago Pereiro
4 min readNov 18, 2020

Systems thinking is a discipline that has been around since 1920s born to illustrate and understand complex systems.

It’s been widely used in fields like biology and engineering but we can use it to better understand a team building software, a washing machine or how COVID-19 transmission works.

“Systems thinking has been described as a language for talking about the complex, interdependent issues managers face every day.”

– Colleen Lannon

The very basics of system thinking

A system, in basics, is a group of elements/parts that interact with each other with a final purpose.

So to define any system we need to identify the following building blocks:

  • Elements/variables: parts that affects the system
  • Interconnections: relationship between the elements. This can be +/- depending on the effect that have in the other variable.
  • Goal/Purpose: what is the system designed to do.

Let’s view it with an example, let’s start with a simple model of COVID-19 transmission.

System goal: Transmission of COVID-19 on a population.

Elements: Transmission events, People Infected, Frequency of contacts and people recovered.

A simple model could be:

In this simple model we can see how the elements are interconnected and we can identify that the system is not just linear. It is the moment to introduce another basic concept on this systems: the feedback loops.

Elements with the interconnections generate feedback loops that can be:

  • Reinforcing loops: when elements are feeding each other (represented with R) making the system output grow even exponentially
  • Balancing loops: when elements are compensating each other (represented with B)

In the model created we can see a Reinforcing loop so the more people is infected the bigger will be the number of transmission events.

But this is just a very basic model, in the reality there are much more elements in place. As people gets infected at least part of them are detected and people observing the reality influence on it introducing new elements.

So let’s model it by adding the following elements: Number of cases detected, Risk perceived, counter measures and perception of risk by the population

We can see that as the number of interconnections grows, the system gets more complex but also describes more accurately our COVID-19 scenario.

So as more cases are detected, the bigger the perceived risk (6) is and so more measures are put place (7,9) reducing the number of contacts and the infection rate and so the Transmission events. Also the fear of the people grows (10) and so the frequency of contacts is reduced (11) leading to also a reduction of the transmission events.

We are now describing 3 balancing loops that reduce the transmission.

We could introduce the impact on the economy but … let’s leave it for another day.

The point is that with this model in place we can see the levers that drive reality of COVID (at least some of them) and so take accurate decisions to influence on the system gets easier.

So, what are the benefits of System thinking or..Why is important to understand a system?

“Every system is perfectly designed to achieve the results it gets”

Improvement Axiom

Why is it helpful? modelling the reality helps us better understand the problem we are facing and so take better informed decisions.

Remember that every system works perfectly to reach the goal for which it was designed, and understanding the system helps influence on them if we have a different goal for it.

We can use system thinking as a tool that allows us to swift between reacting to events into analyse the full picture to get better results.

Even just realising that most of the problems we face are not just action-reaction problems will put us in a position to think twice before acting.

References

Introduction to Systems Thinking Daniel H. Kim

Tools for Systems Thinkers

Fundamentals of Systems Thinking by Pat Kua

Below the surface (another model for COVID-19)

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Yago Pereiro

Product person and Delivery Lead, family man and dad of Wonder Women, curious and traveler, always learning.