Contents
Introduction............................................................................................................................................2
Chapter 1: The Basics.............................................................................................................................3
Chapter 2: A Brief Visit to the Systems Zoo............................................................................................7
Chapter 3: Why Systems Work So Well................................................................................................13
Chapter 4: Why Systems Surprise Us....................................................................................................15
Chapter 5: System Traps and Opportunities.........................................................................................20
Chapter 6: Leverage Points— Places to Intervene in a System.............................................................27
Chapter 7: Living in a World of Systems...............................................................................................32
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,Introduction
Systems thinking will help us manage, adapt, and see the wide range of choices we have before us. It
is a way of thinking that gives us the freedom to identify root causes of problems and see new
opportunities.
A system is a set of things—people, cells, molecules, or whatever—interconnected in such a way that
they produce their own pattern of behavior over time. The system’s response to outside forces is
characteristic of itself, and that response is seldom simple in the real world.
Ever since the Industrial Revolution, Western society has benefited from science, logic, and
reductionism over intuition and holism. Psychologically and politically we would much rather assume
that the cause of a problem is “out there,” rather than “in here.”
Serious problems have been solved by focusing on external agents however, some of our “solutions”
have created further problems. And some problems, those most rooted in the internal structure of
complex systems, have refused to go away.
Hunger, poverty, and war, for example, persist in spite of the analytical ability and technical brilliance
that have been directed toward eradicating them. No one deliberately creates those problems, no
one wants them to persist, but they persist nonetheless. That is because they are intrinsically
systems problems—undesirable behaviors characteristic of the system structures that produce them.
They will yield only as we reclaim our intuition, stop casting blame, see the system as the source of
its own problems, and find the courage and wisdom to restructure it
Systems zoo—a collection of some common and interesting types of systems.
At a time when the world is more messy, more crowded, more interconnected, more
interdependent, and more rapidly changing than ever before, the more ways of seeing, the better.
The systems-thinking lens allows us to reclaim our intuition about whole systems and
- hone our abilities to understand parts
- see interconnections,
- ask “what-if ” questions about possible future behaviors
- be creative and courageous about system redesign.
Then we can use our insights to make a difference in ourselves and our world.
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,Chapter 1: The Basics
A system is an interconnected set of elements that is coherently organized in a way that achieves
something. A system must consist of three kinds of things: elements, interconnections, and a
function or purpose. Systems can be embedded in systems, which are embedded in yet other
systems.
A conglomeration without any particular interconnections or function is no system.
When a living creature dies, it loses its “system-ness.” The multiple interrelations that held it
together no longer function, and it dissipates, although its material remains part of a larger food-web
system.
A system is more than the sum of its parts. It may exhibit adaptive, dynamic, goal-seeking, self-
preserving, and sometimes evolutionary behavior.
Systems can be self-organizing, and often are self-repairing over at least some range of disruptions.
They are resilient, and many of them are evolutionary. Out of one system other completely new,
never-before-imagined systems can arise.
The elements of a system are often the easiest parts to notice, because many of them are visible,
tangible things. Elements do not have to be physical things. Intangibles are also elements of a
system.
Interconnections: the relationships that hold the elements together. It’s easier to learn about a
system’s elements than about its interconnections.
Many of the interconnections in systems operate through the flow of information. Information
holds systems together and plays a great role in determining how they operate
Some interconnections in systems are actual physical flows, such as the water in the tree’s trunk or
the students progressing through a university. Many interconnections are flows of information—
signals that go to decision points or action points within a system. These kinds of interconnections
are often harder to see, but the system reveals them to those who look.
A system’s function or purpose is not necessarily spoken, written, or expressed explicitly, except
through the operation of the system. The best way to deduce the system’s purpose is to watch for a
while to see how the system behaves. Purposes are deduced from behavior, not from rhetoric or
stated goals.
The word function is generally used for a nonhuman system, the word purpose for a human one, but
the distinction is not absolute, since so many systems have both human and nonhuman elements.
One of the most frustrating aspects of systems is that the purposes of subunits may add up to an
overall behavior that no one wants. No one intends to produce a society with rampant drug addiction
and crime, but consider the combined purposes and consequent actions of the actors involved.
Systems can be nested within systems. Therefore, there can be purposes within purposes. Any of
sub-purposes could come into conflict with the overall purpose. Keeping sub-purposes and overall
system purposes in harmony is an essential function of successful systems.
Changing elements usually has the least effect on the system. A system generally goes on being itself,
changing only slowly if at all, even with complete substitutions of its elements—as long as its
interconnections and purposes remain intact.
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, The least obvious part of the system, its function or purpose, is often the most crucial determinant
of the system’s behavior.
If the interconnections change, the system may be greatly altered. If you change the
interconnections in the tree—say that instead of taking in carbon dioxide and emitting oxygen, it
does the reverse—it would no longer be a tree. Changing interconnections in a system can change it
dramatically.
A change in purpose changes a system profoundly, even if every element and interconnection
remains the same.
The least obvious part of the system, its function or purpose, is often the most crucial determinant of
the system’s behavior. Interconnections are also critically important. Changing relationships usually
changes system behavior. The elements, the parts of systems we are most likely to notice, are often
(not always) least important in defining the unique characteristics of the system—unless changing an
element also results in changing relationships or purpose.
A stock is the foundation of any system. Stocks are the elements of the system that you can see, feel,
count, or measure at any given time (e.g. water in the bathtub). A stock does not have to be physical.
A stock is the memory of the history of changing flows within the system.
Stocks change over time through the actions of a flow. Flows are filling and draining, births and
deaths, purchases and sales, growth and decay, deposits and withdrawals, successes and failures. A
stock, then, is the present memory of the history of changing flows within the system.
If you understand the dynamics of stocks and flows—their behavior over time—you understand a
good deal about the behavior of complex systems.
Systems thinkers use graphs of system behavior to understand trends over time, rather than
focusing attention on individual events. We also use behavior-over-time graphs to learn whether the
system is approaching a goal or a limit, and if so, how quickly.
Dynamic equilibrium—its level does not change even though there is still a continuous flow
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