System Structure and Behavior
Introduction
In this post, we will discuss what systems are and how they work. It is important to have this understanding, as we can find systems anywhere in the world - even in our own bodies. In this post, we will talk about what systems consist of, how they work over time, and how systems run themselves.
Key concepts
A system is an interconnected set of elements, which is organised in a way that allows it to achieve a certain goal. Systems consist of three types of things: elements, interconnections and function or purpose. A system can be found in our bodies, for example our circulatory system (shown on picture below). It consists of the heart, blood vessels, arteries and capillaries. Those elements are interconnected through the flow of blood. The function of this system is to make blood circulate and transport nutrients, oxygen, carbon dioxide and hormones to provide nourishment and help in fighting potential deceases. Systems can be both complex and easy processes but they are very important for us to understand.
A system is an interconnected set of elements, which is organised in a way that allows it to achieve a certain goal. Systems consist of three types of things: elements, interconnections and function or purpose. A system can be found in our bodies, for example our circulatory system (shown on picture below). It consists of the heart, blood vessels, arteries and capillaries. Those elements are interconnected through the flow of blood. The function of this system is to make blood circulate and transport nutrients, oxygen, carbon dioxide and hormones to provide nourishment and help in fighting potential deceases. Systems can be both complex and easy processes but they are very important for us to understand.
In order to understand system behavior over time, we can take the example of a bathtub. Imagine a bathtub with some water in it. This bathtub represents a stock. A stock is the foundation of any system, which consists of elements that we can feel, count or measure at any given time. There is an inflow and outflow of water from this stock. Those flows change the stock over time. We can represent it as Figure 1:
If we turn on its faucets, the inflow of water will increase the amount in the stock. If we turn off the faucets and pull the plug, the outflow of water will decrease the stock. This is the representation of how systems behave over a time period; inflows and outflows change the stock of the system.
Now let’s try to understand a slightly more complex system, which can balance and reinforce itself. We take the example of a population. Considering the population of a country as a stock, the inflow would be the births and outflow would be deaths. As represented in Figure 2:
The population knows how reinforce and balance itself. It reinforces through creating new lives, which is the births (inflow). And it balances itself by causing people to die (outflow). This is an example of reinforcing and balancing loops. In the case of fertility and mortality being constant, the system has a simple behavior: depending on which is the bigger loop population can grow or die off. Therefore, we can say, that the stock itself can control the inflows and outflows- so it runs itself.
Balancing feedback loops:
Balancing feedback loops can be found everywhere in systems, whether they develop naturally or are created by humans. An example of a balancing feedback loop is a thermostat, which aims at keeping the room temperature constant.
Complex systems often have multiple self balancing loops, in order to self correct in any situation. There are loops that are activated rarely, such as an emergency cooling system at a nuclear power plant (man made) or our bodies’ ability to maintain temperature in extreme weather (natural).
We determine the strength of a balancing loop by its ability to remain at the desired level. This ability depends on the combination of all parameters and links. These can include accuracy and rapidity of monitoring, quickness and power of response, directness and size of corrective flows. We can also find leverage points in these.
Reinforcing feedback loops:
Feedback loop delays have a large impact on system behavior and often cause them to oscillate. For example, it is difficult to accurately calculate optimal stock if you are getting delayed information about its state, or the state of demand.
It is impossible for a system with long delays to adjust to short term changes. Two examples of this fact are the Soviet Union and General Motors. With size, organizations and systems in general tend to lose flexibility, which is something that has been attempted to be overcome by businesses for a long time.
We measure a delay in feedback relative to the rate of change in the stock that the feedback loop is trying to control. The two extremes of this are overreaction - in the case of an extremely short delay - which causes “chasing your own tail”. On the other hand, an extremely long delay leads to damped or sustained or exploding oscillations. In systems which have a critical point/threshold, such long delays can cause a collapse.
Always ensure to change delays that exist in your system in the right directions, for the consequences may be bigger than you expect.
Conclusion
Understanding the function of a system is very important in both one's personal and professional life. We can understand how a company works, why some decisions are made in a specific way, and, importantly, we can predict outcomes. This provides guidance and clarity. Systems serve as companies’ initial support; therefore, it is important to use them in business.
References:
Meadows, D. (2009). Thinking in systems. London: Earthscan, pp.11-45.
Robb, A. (2018). What Are the Organ Systems of the Human Body?. [online] Study.com. Available at: https://study.com/academy/lesson/what-are-the-organ-systems-of-the-human-body.html [Accessed 27 Oct. 2018].
Meadows, D. (2009). Thinking in systems. London: Earthscan, pp.11-45.
Robb, A. (2018). What Are the Organ Systems of the Human Body?. [online] Study.com. Available at: https://study.com/academy/lesson/what-are-the-organ-systems-of-the-human-body.html [Accessed 27 Oct. 2018].