Title: The Systems Approach
Author: C. West Churchman
Churchman, C. West. (1968). The Systems Approach. New York: Dell Publishing
Date Posted: April 7, 2013
I began using the concepts of systems theory while an intelligence officer during the Vietnam War. Later I applied it to several courses I was teaching at the Rochester (NY) Institute of Technology. One of the most important books to me at that time was this book by Churchman. Churchman’s outline for his book is fundamental to almost every work since.
I. What is a system?
II. Applications of systems thinking.
III. Systems approach to the future.
IV. The systems approach and the human being.
A system is a assemblage of interrelated parts that work together by way of some driving process. Systems are often visualized as component blocks that have connections drawn between them. I used a vending machine to illustrate the concept of a system for my students. The vending machine, say for soft drinks has the following elements or common characteristics. These common characteristics include the following:
1. Systems have a structure that is defined by its parts and processes.
2. Systems are generalizations of reality (thus an abstract system is a model).
3. Systems tend to function in the same way. One can define inputs and outputs material (energy or matter) that is then processed causing it to change in some way.
4. The various parts of a system have functional as well as structural relationships between each other. (A system may have a subsystem.)
5. The fact that functional relationships exist between the parts suggests the flow and transfer of some type of energy and or matter.
6. Systems often exchange energy and/or matter beyond their defined boundary with the outside environment, and other systems, through various input and output processes.
7. Functional relationships can only occur because of the presence of a driving force.
8. The parts that make up a system show some degree of integration – in other words the parts work well together.
Using Churchman’s book to assist students thinking about systems I assigned them to use the example of a soda vending machine to illustrate each of the characteristics above.
A system has a boundary and an environment. That means there is some point where the system ends and its surroundings begin. This is not always easy to define. For example if we consider an elephant as a system, where does the boundary exist. Outside the skin of the elephant? But an elephant has a definite aroma, and is that not part of the system. This very point was one of the things that led to a new form of mathematics, that of fuzzy sets.
But since a system is a model, we may assume we can define the system boundary. Within the boundary we find three kinds of properties:
Elements – are the kinds of parts (things or substances) that make up a system. These parts may be atoms or molecules, or larger bodies of matter like sand grains, rain drops, plants, animals, etc.
Attributes. Characteristics of the elements that may be perceived and measured. For example: quantity, size, color, volume, temperature, and mass.
Relationships: The associations that occur between elements and attributes. These associations are based on cause and effect.
We can define the state of the system by determining the value of its properties (the elements, attributes, and relationships.)
Scientists have examined and classified many types of systems. Some of the classified types include:
Isolated System: A system that has no interactions beyond its boundary layer. Many controlled laboratory experiments are this type of system.
Closed System: - A system that transfers energy, but not matter, across its boundary to the surrounding environment. Our planet is often viewed as a closed system.
Open System:- A system that transfers both matter and energy can cross its boundary to the surrounding environment. Most ecosystems are example of open systems.
There are several other types of systems used in many different fields, such as control systems (electrical engineering) and ecosystems (in ecology and environmental studies.) An ecosystem is a system that models relationships and interactions between the various biotic and abiotic components making up a community or organisms and their surrounding physical environment.
To me they may be better books than Churchman, but anyone approaching systems thinking should first understand what Churchman says. It is the genesis of systems thinking and one book I will keep in my library.
Churchman, C. West. (1968). The Systems Approach. New York: Dell Publishing. ISBN: 978-0440384076