# Systems thinking

Systems thinking is the basis of System Theory .

## Systems thinking in the narrow sense

Relatively old literature on system thinking uses causal loop diagrams and stock-flow diagrams as methodologies to represent systems.

It is called an iceberg model, but when I make these figures, I think of what I am seeing as the "tip of the iceberg" and proceed with the consideration of what is hidden under the surface of the sea. I will try

Also, although specific numbers are not shown in the figure, we will look at the numerical relationships of the elements. We also assume that the values ??change over time.

### Causal loop diagram

A causal loop diagram graphically expresses a relationship such that if A is increased, B will increase, and in order to prevent B from increasing too much, there will be a feedback function that will reduce A in turn.

In this example the only elements are A and B, but in practice we will consider more complex relationships.

### Stock flow diagram

A stock flow diagram can also express a situation in which an increase or decrease is not immediately communicated and remains within an element.

Applying concrete formulas to this gives us System Dynamics .

## Systems thinking in the broadest sense

As of 2022, "systems thinking" can include tools other than causal loop diagrams and stock-flow diagrams. As an author, there are some systems that cannot be represented by causal loop diagrams or stock-flow diagrams, so I think it would be better to think about other systems as well.

If we were to express "system thinking" in a broad sense, we would think of the entire system as a combination of parts and ask questions such as "What are the parts (elements)?" If there is, what is the relationship?", the method of qualitative analysis using diagrams can be said to be "systems thinking".

In the broad sense of system thinking, Quality Way of Making Hypothesis and Business flow analysis are types of system thinking.

Dividing a system into elements and expressing the movement of the elements, which is read as "modeling" in the field of systems engineering , can also be considered a type of systems thinking.