Home | Login | Recent Changes | Search | All Pages | Help

CausalLoops

Causal Loops are one of the tools used in systems thinking. We (DianeGibson and DonGray) have found it easy to read books with causal loop diagrams and admit that "Yes, this makes sense to me, too." However, in practice, we find it much harder to look at a situation, and develop our own causal loops.

In this BoF we're going to share information, ideas, and techniques for learning how to draw causal loops. If you'd like to join us, we're currently planning to have this BoF on Monday night. Look for a sign up sheet when you register. 2003.07.28

I've lifted the following pretty much in tact from When A Butterfly Sneezes by Linda Booth Sweeny. I feel it describes the things to consider when trying to decide if something is a system (or not). Of course, YMMV.

"One simple step is to understand the basic characteristics of systems. The following five questions can get you started.

1. Is it a heap or a system?
   
2. Is the whole greater than the sum of the parts?
   
3. What�s the purpose?
   
4. Are the causes and effects shaped like a circle?
   
5. Are we experiencing d�j� vu?
   

Is it a Heap or a System?

Systems consist of two or more parts, but so do �heaps,� such as a bowl of mixed nuts.

With a heap, nothing changes if you take away or add parts.

With a system, things definitely change if you take away or add parts.

You will find that systems always have a distinctive arrangement between their key elements; thus the wisdom behind the old saying �If you cut a cow in half, you don�t get two cows.�

Is the Whole Greater Than the Sum of Its Parts?

All living systems consist of a huge number of tightly connected interactions. � We�ve all hear the saying, �The whole is greater than the sum of its parts.� In systems thinking, this means that the many interactions among the parts in a system give rise to qualities or properties that you just can�t measure merely by adding up to parts.

What�s the Purpose?

Most systems have a distinct �point� or purpose in relationship to the larger system in which they are embedded. In many social systems, we see subsystems whose purposes can conflict sometimes �

The simple questions we might often forget to ask is this: �What is the purpose of this system?,� whether it be a clique in school, a committee on the school board, or a department in an organization.

Are the Causes and Effects Shaped Like A Circle?

We can think of cause and effect, or causality, as coming in several �shapes.� The shape can be linear �

Systems thinkers have another notion of causality: feedback loops, which have a circular shape. The simplest way to think of these is to imagine that one event causes another event, and that second event comes back around to influence that first cause.

Reinforcing loops cause dramatic growth or collapse. When you hear people say things like �The situation�s totally out of control� or �Things are just snowballing,� chances are there are reinforcing loops at work.

Depending on the situation, a reinforcing loop can be either vicious (amplifying to make something greater, or virtuous (amplifying in the opposite direction, e.g. making something less.)

Balancing loops put limits on dramatic growth and collapse, and ensure that a system fulfills its purpose.

Balancing loops aren�t as noticeable as reinforcing loops, but there are lots of them out there. Because they tend to keep things steady, we can sometimes detect them when we try to change something but get no results.

Are We Experiencing D�j� vu?

Systems thinkers have identified a whole set of common �stories� like this which they call �system archetypes� that occur in different settings."

DonGray 2003.08.03

Paraphrased from Weinberg on systems (I think he stole it somewhere, actually):

A system is a collection of elements that you cannot change independently.

-- JimBullock, 2003.08.04