Ohio Investment Network


Recent Blogs


Pitching Help Desk


Testimonials

"We have already had one investor for $25K, and another who is very involved in the food business, who could be a funder on a much larger level. So we are very pleased, and offer our thanks."
Bruce J.

 BLOG >> Recent

Diagramming Systems [Business Models
Posted on May 9, 2014 @ 08:21:00 AM by Paul Meagher

To attain better mastery of systems theory, I thought that a good exercise would be to diagram a system in the way that Donella Meadows suggested they be diagrammed by using a "stock and flow" diagram. Donella's book, Thinking in Systems: A Primer, provides many examples of system diagrams for many different types of systems. This is one reason it is such a useful book - it provides many templates to get you started with. The system that I chose to develop my own diagram for is Donella's version of the "Ecomomic System" (she calls it the "heart of the economic system"). I chose to diagram this system for two reasons: 1) It is an simple diagram of a complex system that nevertheless provides useful insight, 2) it includes most of the basic devices used in stock and flow systems diagramming. Here is my diagram of the "Economic System" which just tries to copy Donella's version (i.e., learn by copying):

The exercise of copying Donella's systems diagram helped me to recognize some of the finer details of her diagrams. One thing to note is the labels "R" and "B" in the middle of the two loops. The label "R" stands for Reinforcing. In other words, it is a factor that makes the capital stock increase. The label "B" stands for "Balancing". It is a factor that diminishes capital stock. In any system, there is at least one reinforcing component and at least one balancing component. One lesson we might take from this is that when we think about business growth we often focus on the reinforcing component that produces the growth but we should keep in mind that there are also balancing forces preventing that growth from happening. The idea of viral growth suggests only reinforcing growth is at play, but at some point even viral growth gets balanced out. Yin and yang.

Another aspect of the diagram to note is the arrows that point to the two taps that are not part of a loop. These are "control variables" that have an influence on the level of your capital stock. In this case, one control variable on the input tap is the "investment fraction" (fraction of output that is reinvested into the economy) and the other control variable on the output tap is the "capital lifetime" (how quickly infrastructure starts to fail). It is important to note that control variables are not always under the control of someone. Nature can be the controller in some cases. If climate becomes more extreme, the capital lifetime of infrastructure can be reduced significantly. In the case of home heating, the flow of heat out of your building is controlled by the balancing loop of the temperature outside and is moderated by the level of insulation in your house. The control variable, temperature outside, is set by nature.

What distinguishes systems diagrams from other forms of modelling is the use of reinforcing, balancing, and control variables to depict how the entity being modelled works. Other forms of modelling that have arrows pointing from one part to another part might bear a resemblance to systems models, but if they don't conceptualize the arrows as control, reinforcing, or balancing, then they are probably not systems models per se.

According to Peter Senge, "systems thinking is not about fighting complexity with more complexity. It simply means stepping back and seeing patterns that are, when seen clearly, intuitive and easy to grasp". So a stylistic note for systems diagramming is not to get carried away with drawing loops, arrows, and boxes. In many cases, you are looking for the simplist diagram that provides useful insight into the system.

To design my systems diagram I used the http://www.draw.io website. It is a very powerful free online tool for drawing diagrams that I would recommend you try out. It took awhile to find the shape library that I wanted to use to represent the tap symbol. It also took awhile to get used to creating and editing the parts of the diagram but towards the end I found diagramming was happening at a good clip. You can save your diagram in various output formats from svg to png. Join the fun and use draw.io to create your own systems diagrams!

Permalink 

 Archive 
 

Archive


 November 2023 [1]
 June 2023 [1]
 May 2023 [1]
 April 2023 [1]
 March 2023 [6]
 February 2023 [1]
 November 2022 [2]
 October 2022 [2]
 August 2022 [2]
 May 2022 [2]
 April 2022 [4]
 March 2022 [1]
 February 2022 [1]
 January 2022 [2]
 December 2021 [1]
 November 2021 [2]
 October 2021 [1]
 July 2021 [1]
 June 2021 [1]
 May 2021 [3]
 April 2021 [3]
 March 2021 [4]
 February 2021 [1]
 January 2021 [1]
 December 2020 [2]
 November 2020 [1]
 August 2020 [1]
 June 2020 [4]
 May 2020 [1]
 April 2020 [2]
 March 2020 [2]
 February 2020 [1]
 January 2020 [2]
 December 2019 [1]
 November 2019 [2]
 October 2019 [2]
 September 2019 [1]
 July 2019 [1]
 June 2019 [2]
 May 2019 [3]
 April 2019 [5]
 March 2019 [4]
 February 2019 [3]
 January 2019 [3]
 December 2018 [4]
 November 2018 [2]
 September 2018 [2]
 August 2018 [1]
 July 2018 [1]
 June 2018 [1]
 May 2018 [5]
 April 2018 [4]
 March 2018 [2]
 February 2018 [4]
 January 2018 [4]
 December 2017 [2]
 November 2017 [6]
 October 2017 [6]
 September 2017 [6]
 August 2017 [2]
 July 2017 [2]
 June 2017 [5]
 May 2017 [7]
 April 2017 [6]
 March 2017 [8]
 February 2017 [7]
 January 2017 [9]
 December 2016 [7]
 November 2016 [7]
 October 2016 [5]
 September 2016 [5]
 August 2016 [4]
 July 2016 [6]
 June 2016 [5]
 May 2016 [10]
 April 2016 [12]
 March 2016 [10]
 February 2016 [11]
 January 2016 [12]
 December 2015 [6]
 November 2015 [8]
 October 2015 [12]
 September 2015 [10]
 August 2015 [14]
 July 2015 [9]
 June 2015 [9]
 May 2015 [10]
 April 2015 [9]
 March 2015 [8]
 February 2015 [8]
 January 2015 [5]
 December 2014 [11]
 November 2014 [10]
 October 2014 [10]
 September 2014 [8]
 August 2014 [7]
 July 2014 [5]
 June 2014 [7]
 May 2014 [6]
 April 2014 [3]
 March 2014 [8]
 February 2014 [6]
 January 2014 [5]
 December 2013 [5]
 November 2013 [3]
 October 2013 [4]
 September 2013 [11]
 August 2013 [4]
 July 2013 [8]
 June 2013 [10]
 May 2013 [14]
 April 2013 [12]
 March 2013 [11]
 February 2013 [19]
 January 2013 [20]
 December 2012 [5]
 November 2012 [1]
 October 2012 [3]
 September 2012 [1]
 August 2012 [1]
 July 2012 [1]
 June 2012 [2]


Categories


 Agriculture [77]
 Bayesian Inference [14]
 Books [18]
 Business Models [24]
 Causal Inference [2]
 Creativity [7]
 Decision Making [17]
 Decision Trees [8]
 Definitions [1]
 Design [38]
 Eco-Green [4]
 Economics [14]
 Education [10]
 Energy [0]
 Entrepreneurship [74]
 Events [7]
 Farming [21]
 Finance [30]
 Future [15]
 Growth [19]
 Investing [25]
 Lean Startup [10]
 Leisure [5]
 Lens Model [9]
 Making [1]
 Management [12]
 Motivation [3]
 Nature [22]
 Patents & Trademarks [1]
 Permaculture [36]
 Psychology [2]
 Real Estate [5]
 Robots [1]
 Selling [12]
 Site News [17]
 Startups [12]
 Statistics [3]
 Systems Thinking [3]
 Trends [11]
 Useful Links [3]
 Valuation [1]
 Venture Capital [5]
 Video [2]
 Writing [2]